[PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Goffredo Baroncelli]

Hi all,

This serie of patches adds a new command called "btrfs filesystem
disk-usage". I added this command because it is not so easy to get
the information about the disk usage from the command "fi df" and "fi show".

>From the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  disk-usage is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem disk-usage --help
usage: btrfs filesystem disk-usage [-d][-s][-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k	Set KB (1024 bytes) as unit
    -s	Don't show the summary section
    -d	Don't show the detail section

$ ./btrfs filesystem disk-usage /
Path: /
Summary:
  Disk_size:		     72.57GB
  Disk_allocated:	     25.10GB
  Disk_unallocated:	     47.48GB
  Logical_size:		     23.06GB
  Used:			     11.01GB
  Free_(Estimated):	     55.66GB	(Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:	        92 %

Details:
  Chunk-type  Mode      Chunk-size Logical-size        Used
  Data        Single       21.01GB      21.01GB     10.34GB
  System      DUP          80.00MB      40.00MB      4.00KB
  System      Single        4.00MB       4.00MB        0.00
  Metadata    DUP           4.00GB       2.00GB    686.93MB
  Metadata    Single        8.00MB       8.00MB        0.00

Where:
	Disk_size			-> sum of sizes of teh disks
	Disk_allocated			-> sum of chunk sizes
	Disk_unallocated		-> Disk_size - Disk_allocated
	Logical_size			-> sum of logical area sizes
	Used				-> logical area used
	Free_(Estimated)		-> on the basis of allocated
					   chunk, an estrapolation of
					   the free space
	Data_to_disk_ratio		-> ration between the space occuped
					   by a chunk and the real space
					   available ( due to duplication
					   and/or RAID level)
	Chunk-type			-> kind of chunk
	Mode				-> allocation policy of a chunk
	Chunk-size			-> area of disk(s) occuped by the
					   chunk (see it as raw space used)
	Logical-size			-> logical area size of the chunk
	Used				-> portion of the logical area
					   used by the filesystem



You can pull this change from 
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Comments are welcome.

BR
Goffredo Baroncelli

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
	

[PATCH 1/2] Add btrfs filesystem disk-usage command

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

The  command  btrfs  filesystem  disk-usage is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
---
 cmds-filesystem.c |  282 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 282 insertions(+)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index b1457de..72f9b36 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <uuid/uuid.h>
 #include <ctype.h>
+#include <sys/vfs.h>
 
 #include "kerncompat.h"
 #include "ctree.h"
@@ -153,6 +154,286 @@ static int cmd_df(int argc, char **argv)
 	return 0;
 }
 
+static u64 disk_size( char *path){
+	struct statfs	sfs;
+
+	if( statfs(path, &sfs) < 0 )
+		return 0;
+	else
+		return sfs.f_bsize * sfs.f_blocks;
+
+}
+
+
+static void print_string(char *s, int w)
+{
+	int	i;
+
+	printf("%s", s);
+	for( i = strlen(s) ; i < w ; i++ ) 
+		putchar(' ');
+}
+
+#define DF_SHOW_SUMMARY 	(1<<1)
+#define DF_SHOW_DETAIL		(1<<2)
+#define DF_HUMAN_UNIT		(1<<3)
+
+static void pretty_sizes_r(u64 size, int w, int mode)
+{
+	if( mode & DF_HUMAN_UNIT ){
+		char *s = pretty_sizes(size);
+		printf("%*s", w, s);
+		free(s);
+	} else {
+		printf("%*llu", w, size/1024);
+
+	}
+}
+
+static int _cmd_disk_usage(char *path, int mode)
+{
+	struct btrfs_ioctl_space_args *sargs;
+	u64 count = 0, i;
+	int ret;
+	int fd;
+	int e, width;
+	u64  total_disk;		/* fielsystem size == sum of
+					   disk sizes */
+	u64  total_chunks;		/* sum of chunks sizes on disk(s) */
+	u64  total_used;		/* logical space used */
+	u64  total_free;		/* logical space un-used */
+	double K;
+	
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
+	if (!sargs)
+		return -ENOMEM;
+
+	sargs->space_slots = 0;
+	sargs->total_spaces = 0;
+
+	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
+	e = errno;
+	if (ret) {
+		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
+			path, strerror(e));
+		free(sargs);
+		return ret;
+	}
+	if (!sargs->total_spaces)
+		return 0;
+
+	count = sargs->total_spaces;
+
+	sargs = realloc(sargs, sizeof(struct btrfs_ioctl_space_args) +
+			(count * sizeof(struct btrfs_ioctl_space_info)));
+	if (!sargs)
+		return -ENOMEM;
+
+	sargs->space_slots = count;
+	sargs->total_spaces = 0;
+
+	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
+	e = errno;
+	if (ret) {
+		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
+			path, strerror(e));
+		close(fd);
+		free(sargs);
+		return ret;
+	}
+
+	total_disk = disk_size(path);
+	e = errno;
+	if( total_disk == 0 ){
+		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
+			path, strerror(e));
+		close(fd);
+		free(sargs);
+		return ret;
+	}
+		
+	total_chunks = total_used = total_free = 0;
+
+	for (i = 0; i < sargs->total_spaces; i++) {
+		int  ratio=1;
+		u64  allocated;
+
+		u64 flags = sargs->spaces[i].flags;
+
+		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
+			ratio=1;
+		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
+			ratio=2;
+		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
+			ratio=2;
+		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
+			ratio=2;
+		} else {
+			ratio=1;
+		}
+
+		allocated = sargs->spaces[i].total_bytes * ratio;
+
+		total_chunks += allocated;
+		total_used += sargs->spaces[i].used_bytes;
+		total_free += (sargs->spaces[i].total_bytes - 
+					sargs->spaces[i].used_bytes);
+
+	}
+	K = ((double)total_used + (double)total_free) /
+	                (double)total_chunks;
+
+	if( mode & DF_HUMAN_UNIT )
+		width = 12;
+	else
+		width = 18;
+
+	printf("Path: %s\n", path);
+	if( mode & DF_SHOW_SUMMARY ){
+		printf("Summary:\n");
+		printf("  Disk_size:\t\t");
+		pretty_sizes_r(total_disk, width, mode);
+		printf("\n  Disk_allocated:\t");
+		pretty_sizes_r(total_chunks, width, mode);
+		printf("\n  Disk_unallocated:\t"); 
+		pretty_sizes_r(total_disk-total_chunks, width, mode);
+		printf("\n  Logical_size:\t\t"); 
+		pretty_sizes_r(total_used+total_free, width, mode);
+		printf("\n  Used:\t\t\t"); 
+		pretty_sizes_r(total_used, width, mode);
+		printf("\n  Free_(Estimated):\t");
+		pretty_sizes_r((u64)(K*total_disk-total_used), width, mode);
+		printf("\t(Max: ");
+		pretty_sizes_r(total_disk-total_chunks+total_free, 
+				0, mode );
+		printf(", Min: ");
+		pretty_sizes_r((total_disk-total_chunks)/2+total_free, 
+				0, mode );
+		printf(")\n  Data_to_disk_ratio:\t%*.0f %%\n",
+			width-2, K*100);
+	}
+
+	if( ( mode & DF_SHOW_DETAIL ) && ( mode & DF_SHOW_SUMMARY ) )
+		printf("\n");
+
+	if( mode & DF_SHOW_DETAIL ){
+		/* Remember: the terminals have maximum 80 columns
+		   do not believe to who says otherwise */
+		printf("Details:\n");
+		printf("  %-12s%-8s%*s%*s%*s\n",
+			"Chunk-type", 
+			"Mode",
+			width, "Chunk-size", 
+			1+width, "Logical-size", 
+			width, "Used"
+		);
+
+		for (i = 0; i < sargs->total_spaces; i++) {
+			char *description="";
+			int  ratio=1;
+			char *r_mode;
+			u64 allocated;
+
+			u64 flags = sargs->spaces[i].flags;
+
+			if (flags & BTRFS_BLOCK_GROUP_DATA) {
+				if (flags & BTRFS_BLOCK_GROUP_METADATA){
+					description = "Data+M.data";
+				} else {
+					description = "Data";
+				}
+			} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+				description = "System";
+			} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
+				description = "Metadata";
+			}
+
+			if (flags & BTRFS_BLOCK_GROUP_RAID0) {
+				r_mode = "RAID0";
+				ratio=1;
+			} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
+				r_mode = "RAID1";
+				ratio=2;
+			} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
+				r_mode = "DUP";
+				ratio=2;
+			} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
+				r_mode = "RAID10";
+				ratio=2;
+			} else {
+				r_mode = "Single";
+				ratio=1;
+			}
+
+			allocated = sargs->spaces[i].total_bytes * ratio;
+
+			printf("  ");
+			print_string(description,12);
+			print_string(r_mode, 8);
+			pretty_sizes_r(allocated, width, mode);
+			pretty_sizes_r(sargs->spaces[i].total_bytes ,
+				    width+1, mode);
+	
+			pretty_sizes_r(sargs->spaces[i].used_bytes, 
+						width, mode);
+			printf("\n");
+
+		}
+	}
+	free(sargs);
+
+	return 0;
+}
+
+static const char * const cmd_disk_usage_usage[] = {
+	"btrfs filesystem disk-usage [-d][-s][-k] <path> [<path>..]",
+	"Show space usage information for a mount point(s).",
+	"",
+	"-k\tSet KB (1024 bytes) as unit",
+	"-s\tDon't show the summary section",
+	"-d\tDon't show the detail section",
+	NULL
+};
+
+static int cmd_disk_usage(int argc, char **argv)
+{
+
+	int 	flags=DF_SHOW_SUMMARY|DF_SHOW_DETAIL|DF_HUMAN_UNIT;
+	int	i, more_than_one=0;
+
+	if (check_argc_min(argc, 2))
+		usage(cmd_df_usage);
+
+	for(i=1; i< argc ; i++){
+		if(!strcmp(argv[i],"-d"))
+			flags &= ~DF_SHOW_DETAIL;
+		else if(!strcmp(argv[i],"-s"))
+			flags &= ~DF_SHOW_SUMMARY;
+		else if(!strcmp(argv[i],"-k"))
+			flags &= ~DF_HUMAN_UNIT;
+		else{
+			int r;
+			if(more_than_one)
+				printf("\n");
+			r = _cmd_disk_usage(argv[i], flags);
+			if( r ) return r;
+			more_than_one=1;
+		}
+
+	}
+
+	return 0;
+}	
+	
+
+	
 static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
 {
 	char uuidbuf[37];
@@ -530,6 +811,7 @@ static int cmd_label(int argc, char **argv)
 const struct cmd_group filesystem_cmd_group = {
 	filesystem_cmd_group_usage, NULL, {
 		{ "df", cmd_df, cmd_df_usage, NULL, 0 },
+		{ "disk-usage", cmd_disk_usage, cmd_disk_usage_usage, NULL, 0 },
 		{ "show", cmd_show, cmd_show_usage, NULL, 0 },
 		{ "sync", cmd_sync, cmd_sync_usage, NULL, 0 },
 		{ "defragment", cmd_defrag, cmd_defrag_usage, NULL, 0 },
-- 
1.7.10.4

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..3215216 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem disk-usage\fP\fI [-s][-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem disk-usage\fP [-s][-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Don't show the summary section
+
+\fB-d\fP Don't show the detail section
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem disk-usage\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem disk-usage\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Chris Mason]

On Tue, Oct 02, 2012 at 12:36:08PM -0600, Goffredo Baroncelli wrote:
> Hi all,
> 
> This serie of patches adds a new command called "btrfs filesystem
> disk-usage". I added this command because it is not so easy to get
> the information about the disk usage from the command "fi df" and "fi show".
> 
> From the man page (see 2nd patch):

I like it, thanks.  Could you please update btrfs fi df to show this
instead of adding a new command though?

-chris

Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Goffredo Baroncelli]

On Wed, Oct 3, 2012 at 1:46 AM, Chris Mason <chris.mason@fusionio.com> wrote:
[...]
> I like it, thanks.  Could you please update btrfs fi df to show this
> instead of adding a new command though?

Hi Chris,
no problem to update the patches, however I have one suggestion:
- leave "btrfs fi df" as is to no break any script (if any) which
would uses it. Hide it from the help and deprecating it in the man
page. This because the output is very different.
- renaming "btrfs fi disk-usage" in "btrfs fi disk-free", which make sense.

Let me know which choiche you prefer.

BR
G.Baroncelli






>
> -chris

Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Roman Mamedov]

[-- Attachment #1: Type: text/plain, Size: 1271 bytes --]

On Wed, 3 Oct 2012 08:22:06 +0200
Goffredo Baroncelli <kreijack@gmail.com> wrote:

> On Wed, Oct 3, 2012 at 1:46 AM, Chris Mason <chris.mason@fusionio.com> wrote:
> [...]
> > I like it, thanks.  Could you please update btrfs fi df to show this
> > instead of adding a new command though?
> 
> Hi Chris,
> no problem to update the patches, however I have one suggestion:
> - leave "btrfs fi df" as is to no break any script (if any) which
> would uses it. Hide it from the help and deprecating it in the man
> page. This because the output is very different.
> - renaming "btrfs fi disk-usage" in "btrfs fi disk-free", which make sense.

1) btrfs is still labeled experimental, so no script author should have
seriously relied on utilities text output to stay unchanged long-term;
personally I don't see modifying it (especially not in some superficial way,
but as a part of major improvement) to be a problem;

2) "disk-usage" and "disk-free" are both way too awkward and too long to type,
compared to "fi df", and "df" is the expected shorthand for "disk free" in the
UNIX land.

-- 
With respect,
Roman

~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Stallman had a printer,
with code he could not see.
So he began to tinker,
and set the software free."

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Sébastien Maury]

Hi,

Thanks for this patch.

Personally, i don't mind any of the propositions as the developpement  
is still in progress and may be adapted.
Furthermore, as Roman said, df is more well known for unix users.

Thanks to your work on that, i've started developing a bunch of  
scripts for monitoring btrfs disk usage (and also for monitoring  
snapper if anyone use it) through nagios.

Regards.
Sébastien

Roman Mamedov <rm@romanrm.ru> a écrit :

> On Wed, 3 Oct 2012 08:22:06 +0200
> Goffredo Baroncelli <kreijack@gmail.com> wrote:
>
>> On Wed, Oct 3, 2012 at 1:46 AM, Chris Mason   
>> <chris.mason@fusionio.com> wrote:
>> [...]
>> > I like it, thanks.  Could you please update btrfs fi df to show this
>> > instead of adding a new command though?
>>
>> Hi Chris,
>> no problem to update the patches, however I have one suggestion:
>> - leave "btrfs fi df" as is to no break any script (if any) which
>> would uses it. Hide it from the help and deprecating it in the man
>> page. This because the output is very different.
>> - renaming "btrfs fi disk-usage" in "btrfs fi disk-free", which make sense.
>
> 1) btrfs is still labeled experimental, so no script author should have
> seriously relied on utilities text output to stay unchanged long-term;
> personally I don't see modifying it (especially not in some superficial way,
> but as a part of major improvement) to be a problem;
>
> 2) "disk-usage" and "disk-free" are both way too awkward and too   
> long to type,
> compared to "fi df", and "df" is the expected shorthand for "disk   
> free" in the
> UNIX land.
>
> --
> With respect,
> Roman
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
> "Stallman had a printer,
> with code he could not see.
> So he began to tinker,
> and set the software free."
>

----------------------------------------------------------------
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Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Martin Steigerwald]

Am Mittwoch, 3. Oktober 2012 schrieb Roman Mamedov:
> On Wed, 3 Oct 2012 08:22:06 +0200
> 
> Goffredo Baroncelli <kreijack@gmail.com> wrote:
> > On Wed, Oct 3, 2012 at 1:46 AM, Chris Mason
> > <chris.mason@fusionio.com> wrote: [...]
> > 
> > > I like it, thanks.  Could you please update btrfs fi df to show
> > > this instead of adding a new command though?
> > 
> > Hi Chris,
> > no problem to update the patches, however I have one suggestion:
> > - leave "btrfs fi df" as is to no break any script (if any) which
> > would uses it. Hide it from the help and deprecating it in the man
> > page. This because the output is very different.
> > - renaming "btrfs fi disk-usage" in "btrfs fi disk-free", which make
> > sense.
> 
> 1) btrfs is still labeled experimental, so no script author should have
> seriously relied on utilities text output to stay unchanged long-term;
> personally I don't see modifying it (especially not in some superficial
> way, but as a part of major improvement) to be a problem;

I am not fond of parsing command output unless using specific options that 
some commands provide to just provide one value. I.e. if the command 
provides options specifically for scripts parsing output. And if I do it 
nonetheless, I am not surprised when it breaks at a time, like with find -
ls which now reports decimal part of file modification timestamps.

I think having a library with a function to get those values via a defined 
API would be way to go. Or querying such stuff via udisks or whatever.

I am very happy to see better size reporting.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: [PATCH][BTRFS-PROGS] btrfs filesystem disk-usage

[Chris Mason]

On Wed, Oct 03, 2012 at 12:22:06AM -0600, Goffredo Baroncelli wrote:
> On Wed, Oct 3, 2012 at 1:46 AM, Chris Mason <chris.mason@fusionio.com> wrote:
> [...]
> > I like it, thanks.  Could you please update btrfs fi df to show this
> > instead of adding a new command though?
> 
> Hi Chris,
> no problem to update the patches, however I have one suggestion:
> - leave "btrfs fi df" as is to no break any script (if any) which
> would uses it. Hide it from the help and deprecating it in the man
> page. This because the output is very different.
> - renaming "btrfs fi disk-usage" in "btrfs fi disk-free", which make sense.
> 
> Let me know which choiche you prefer.

I think it is better to replace btrfs fi df.  There should not be many
scripts relying on it yet.

-chris

[PATCH][BTRFS-PROGS][V1] btrfs filesystem df

[Goffredo Baroncelli]

This serie of patches updated the command "btrfs filesystem
df". I update this command because it is not so easy to get
the information about the disk usage from the command "fi df" and "fi show".

>From the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-d][-s][-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit
    -s  Don't show the summary section
    -d  Don't show the detail section

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Details:
  Chunk-type  Mode      Chunk-size Logical-size        Used
  Data        Single       21.01GB      21.01GB     10.34GB
  System      DUP          80.00MB      40.00MB      4.00KB
  System      Single        4.00MB       4.00MB        0.00
  Metadata    DUP           4.00GB       2.00GB    686.93MB
  Metadata    Single        8.00MB       8.00MB        0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Chunk-type                      -> kind of chunk
        Mode                            -> allocation policy of a chunk
        Chunk-size                      -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Logical-size                    -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Comments are welcome.

BR
Goffredo Baroncelli

Changelog:
V0->V1          Change the name of command from disk-usage to df

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..ed20448 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-s][-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-s][-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Don't show the summary section
+
+\fB-d\fP Don't show the detail section
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH][BTRFS-PROGS][V2] btrfs filesystem df

[Goffredo Baroncelli]

>From the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-d|-s][-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit
    -s  Show the summary section only
    -d  Show the detail section only

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Details:
  Chunk-type  Mode      Chunk_size Logical_size        Used
  Data        Single       21.01GB      21.01GB     10.34GB
  System      DUP          80.00MB      40.00MB      4.00KB
  System      Single        4.00MB       4.00MB        0.00
  Metadata    DUP           4.00GB       2.00GB    686.93MB
  Metadata    Single        8.00MB       8.00MB        0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Chunk_type                      -> kind of chunk
        Mode                            -> allocation policy of a chunk
        Chunk_size                      -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Logical_size                    -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Please pull.

BR
Goffredo Baroncelli

Changelog:
V0->V1          Change the name of command from disk-usage to df
V1->V2		Uses getopt(); replace "-" with "_"; change the behaviour
		of the switches '-s' and '-d'.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..0db588f 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-s|-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-s|-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Show the summary section only
+
+\fB-d\fP Show the detail section only
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH][BTRFS-PROGS][V3] btrfs filesystem df

[Goffredo Baroncelli]

Hi Chris,

this serie of patches updated the command "btrfs filesystem
df". I update this command because it is not so easy to get
the information about the disk usage from the command "fi df" and "fi show".
This patch was the result of some discussions on the btrfs 
mailing list. Many thanks to all the contributors.

>From the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Details:
  Chunk_type  Mode     Size_(disk) Size_(logical)     Used
  Data        Single       21.01GB      21.01GB     10.34GB
  System      DUP          80.00MB      40.00MB      4.00KB
  System      Single        4.00MB       4.00MB        0.00
  Metadata    DUP           4.00GB       2.00GB    686.93MB
  Metadata    Single        8.00MB       8.00MB        0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Chunk_type                      -> kind of chunk
        Mode                            -> allocation policy of a chunk
        Size_(disk)                     -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Size_(logical)                  -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Please pull.

BR
Goffredo Baroncelli

Changelog:
V0->V1          Change the name of command from disk-usage to df
V1->V2          Uses getopt(); replace "-" with "_"; change the behaviour
                of the switches '-s' and '-d'.
V2->V3		Removed the options '-s' and '-d'; replaced Chunk-size 
                and Logical-size with Size_(disk) and Size_(logical).
		Update the man page.

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..96c9239 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBChunk\ type\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH][BTRFS-PROGS][V4] btrfs filesystem df

[Goffredo Baroncelli]

Hi Chris,

this serie of patches updated the command "btrfs filesystem
df". I update this command because it is not so easy to get
the information about the disk usage from the command "fi df" and "fi show".
This patch was the result of some discussions on the btrfs 
mailing list. Many thanks to all the contributors.

from the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Allocated_area:
  Type        Mode       Size_(disk)    Size_(logical)          Used
  Data        Single         21.01GB           21.01GB       12.77GB
  System      DUP            80.00MB           40.00MB        4.00KB
  System      Single          4.00MB            4.00MB          0.00
  Metadata    DUP             4.00GB            2.00GB      709.63MB
  Metadata    Single          8.00MB            8.00MB          0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Type				-> kind of chunk
        Mode                            -> allocation policy of a chunk
        Size_(disk)                     -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Size_(logical)                  -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Please pull.

BR
Goffredo Baroncelli

Changelog:
V3->V4		Removed the switch -d -s from getopt(), aligned the
		column Size_(logical), renamed the fields:
		- Details -> Allocated_area
		- Chunk_type -> Type
V2->V3          Removed the options '-s' and '-d'; replaced Chunk-size 
                and Logical-size with Size_(disk) and Size_(logical).
                Update the man page.
V1->V2          Uses getopt(); replace "-" with "_"; change the behaviour
                of the switches '-s' and '-d'.
V0->V1          Change the name of command from disk-usage to df

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..ecd0916 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBType\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH][BTRFS-PROGS][V6] btrfs filesystem df

[Goffredo Baroncelli]

Hi Chris,

this serie of patches updated the command "btrfs filesystem
df". I update this command because it is not so easy to get
the information about the disk usage from the command "fi df" and "fi show".
This patch was the result of some discussions on the btrfs 
mailing list. Many thanks to all the contributors.

from the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Allocated_area:
  Type        Mode       Size_(disk)    Size_(logical)          Used
  Data        Single         21.01GB           21.01GB       12.77GB
  System      DUP            80.00MB           40.00MB        4.00KB
  System      Single          4.00MB            4.00MB          0.00
  Metadata    DUP             4.00GB            2.00GB      709.63MB
  Metadata    Single          8.00MB            8.00MB          0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Type				-> kind of chunk
        Mode                            -> allocation policy of a chunk
        Size_(disk)                     -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Size_(logical)                  -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Please pull.

Signed-off-by: Goffredo Baroncelli <kreijack@gmail.com>

BR
Goffredo Baroncelli

Changelog:
V5->V6		Th V5 was a wrong patch, please discard it.
V4->V5		Add a close(fd) to avoid file descriptor leaking
V3->V4		Removed the switch -d -s from getopt(), aligned the
		column Size_(logical), renamed the fields:
		- Details -> Allocated_area
		- Chunk_type -> Type
V2->V3          Removed the options '-s' and '-d'; replaced Chunk-size 
                and Logical-size with Size_(disk) and Size_(logical).
                Update the man page.
V1->V2          Uses getopt(); replace "-" with "_"; change the behaviour
                of the switches '-s' and '-d'.
V0->V1          Change the name of command from disk-usage to df

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 9222580..7048273 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -242,6 +244,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBType\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4