[linux-lvm] WebMin LVM module development

[linux-lvm] WebMin LVM module development

[Michael Boman]

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Hi,

for the past week I've been working on a WebMin (http://www.webmin.com)
module for LVM.

I have a few questions I need to get answered as well as I seek people
that is willing to try the LVM module out.

My questions are:
- How can I check what PV's are availble to use with a VG. I know the
pvscan command, but it takes quite a long while to complete and I wonder
if there is any shortcuts to find what PV's that is free to use with a
VG.

- I have problem using MD as a PV of my VG, any hints what it can be?
<output>
mike:/mnt# vgextend vg_test /dev/md0
vgextend -- INFO: maximum logical volume size is 255.99 Gigabyte
vgextend -- ERROR: no physical volumes usable to extend volume group
"vg_test"
</output>

Seeking bug-hunters and feedback:
 I'd like to offer the oppertunity for you guy's (and gal's) that are
living on the edge to try out my WebMin LVM module. It's not fully
operational yet (Can only display VG's and assosiated info as well as
create VG's), but I am hoping that a early beta release will provide me
with enuff feedback to make this a good and useful module to WebMin.

The code is under GNU GPL License version 2 or later, and currently
given out on a per-request basis. I nor the company I work for offers no
garranty that it wont eat your data etc.. #include <std/disclaimer.txt>
as per usual.

Jargon file for the uninformed:
MD = Multiple Devices, software raid.
PV = Physical Volume
PE = Physical Extent
LV = Logical Volume
VG = Volume Group

Best regards
 Michael Boman

PS
 Sorry for cross-posting here, but I wanted to make sure all relivant
parties got informed.
DS

-- 
"eLINUX  ---  Enabling the Net Economy on Linux"
----------------------------------------------------------
Michael Boman                   eLinux Pte Ltd
Technical Consultant            http://www.elinux.com.sg
michael@elinux.com.sg           Tel:    (65)  227 6180
                                Fax:    (65)  227 5808
----------------------------------------------------------

[-- Attachment #2: Card for Michael Boman --]
[-- Type: text/x-vcard, Size: 394 bytes --]

begin:vcard 
n:Boman;Michael
tel;cell:+65 9855 1734
tel;fax:+65 227 5808
tel;work:+65 227 6180
x-mozilla-html:FALSE
url:http://www.elinux.com.sg
org:eLinux Pte Ltd;Technical Division
version:2.1
email;internet:michael@elinux.com.sg
title:Technical Consultant
adr;quoted-printable:;;3 Shenton Way=0D=0A#22-09 Shenton House;Singapore;;068805;Singapore
x-mozilla-cpt:;0
fn:Michael Boman
end:vcard

Re: [linux-lvm] WebMin LVM module development

[Heinz J. Mauelshagen]

On Wed, Dec 06, 2000 at 05:43:55PM +0800, Michael Boman wrote:
> Hi,
> 
> for the past week I've been working on a WebMin (http://www.webmin.com)
> module for LVM.
> 
> I have a few questions I need to get answered as well as I seek people
> that is willing to try the LVM module out.
> 
> My questions are:
> - How can I check what PV's are availble to use with a VG. I know the
> pvscan command, but it takes quite a long while to complete and I wonder
> if there is any shortcuts to find what PV's that is free to use with a
> VG.

No. pvscan's purpose is to do that.
You probably saw the "-n" option to search for free PVs?

> 
> - I have problem using MD as a PV of my VG, any hints what it can be?
> <output>
> mike:/mnt# vgextend vg_test /dev/md0
> vgextend -- INFO: maximum logical volume size is 255.99 Gigabyte
> vgextend -- ERROR: no physical volumes usable to extend volume group
> "vg_test"
> </output>

That's a bug which in 0.9.
There's a fix in 0.8.1 which probaly didn't make it.
0.9.1 should fix this again.

> 
> Seeking bug-hunters and feedback:
>  I'd like to offer the oppertunity for you guy's (and gal's) that are
> living on the edge to try out my WebMin LVM module. It's not fully
> operational yet (Can only display VG's and assosiated info as well as
> create VG's), but I am hoping that a early beta release will provide me
> with enuff feedback to make this a good and useful module to WebMin.
> 
> The code is under GNU GPL License version 2 or later, and currently
> given out on a per-request basis. I nor the company I work for offers no
> garranty that it wont eat your data etc.. #include <std/disclaimer.txt>
> as per usual.
> 
> Jargon file for the uninformed:
> MD = Multiple Devices, software raid.
> PV = Physical Volume
> PE = Physical Extent
> LV = Logical Volume
> VG = Volume Group
> 
> Best regards
>  Michael Boman
> 
> PS
>  Sorry for cross-posting here, but I wanted to make sure all relivant
> parties got informed.
> DS
> 
> -- 
> "eLINUX  ---  Enabling the Net Economy on Linux"
> ----------------------------------------------------------
> Michael Boman                   eLinux Pte Ltd
> Technical Consultant            http://www.elinux.com.sg
> michael@elinux.com.sg           Tel:    (65)  227 6180
>                                 Fax:    (65)  227 5808
> ----------------------------------------------------------
Content-Description: Card for Michael Boman


-- 

Regards,
Heinz      -- The LVM guy --

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Bartningstr. 12
                                                  64289 Darmstadt
                                                  Germany
Mauelshagen@Sistina.com                           +49 6151 7103 86
                                                       FAX 7103 96
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

[linux-lvm] Re: WebMin LVM module development

[Luca Berra]

On Wed, Dec 06, 2000 at 05:43:55PM +0800, Michael Boman wrote:
> 
> - I have problem using MD as a PV of my VG, any hints what it can be?
> <output>
> mike:/mnt# vgextend vg_test /dev/md0
> vgextend -- INFO: maximum logical volume size is 255.99 Gigabyte
> vgextend -- ERROR: no physical volumes usable to extend volume group
> "vg_test"
> </output>

It's a known problem,
LVM 0.8final does not work
LVM 0.8.1 does work
LVM 0.9 does not again

Tomorrow is holiday in Milan, so i will try to give it a look

Regards,
L.

-- 
Luca Berra -- bluca@comedia.it
    Communication Media & Services S.r.l.

Re: [linux-lvm] Re: WebMin LVM module development

[Steven Lembark]

> Tomorrow is holiday in Milan, so i will try to give it a look

hey, what else would you want to do on your holiday :-)

-- 
 Steven Lembark                                   2930 W. Palmer St.
                                                 Chicago, IL  60647
 lembark@wrkhors.com                                   800-762-1582

[linux-lvm] lvm 0.9 + raid (Was: WebMin LVM module development)

[Luca Berra]

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On Wed, Dec 06, 2000 at 07:49:35PM +0100, Luca Berra wrote:
> On Wed, Dec 06, 2000 at 05:43:55PM +0800, Michael Boman wrote:
> > 
> > - I have problem using MD as a PV of my VG, any hints what it can be?
...
> Tomorrow is holiday in Milan, so i will try to give it a look

here it is, or so i hope...
i dinna give it thorough testing, but it seems to work for me

comments on the patch:
Makefile.in: just put a version number in the library,
             so i can have different versions installed
pv_get_size.c: squashed an old bug that reappeared
vg_read_from_pv.c: it would have failed if pv_read said it was an MD, i also
              catch LVM_EPV_READ_PV_EXPORTED, since this is done in other
              places also
pv_read_uuidlist.c: same as above, this seems the right thing to me, but now
              lvm 0.8 tools dont' work anymore on this vg, 0.8.1 seems to
              work ok (?!?)
liblvm.h and vg_remove_dir_and_group_and_nodes.c: this is to work around a probable
              kernel bug with lvm and devfs, if the dev/vgXX directory was removed
			  it was the impossible to fill it again with devices.
			  I also believe that the kernel should create the lvm devices with devfs
			  but it doesn't.

Regards
L.
-- 
Luca Berra -- bluca@comedia.it
    Communication Media & Services S.r.l.

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--- LVM/0.9/tools/lib/pv_get_size.c.bluca.orig	Mon Nov 13 01:20:11 2000
+++ LVM/0.9/tools/lib/pv_get_size.c	Sun Nov 26 10:53:09 2000
@@ -87,6 +87,7 @@
       goto pv_get_size_end;
    }
 
+   memset ( disk_dev_name, 0, sizeof ( disk_dev_name));
    if ( ( cache_entry = lvm_dir_cache_find ( dev_name)) != NULL) {
       if ( lvm_check_partitioned_dev ( cache_entry->st_rdev) == TRUE) {
          st_rdev = cache_entry->st_rdev -
@@ -96,14 +97,14 @@
             if ( dir_cache[i].st_rdev == st_rdev)
                break;
          }
-      }
+         strncpy ( disk_dev_name, dir_cache[i].dev_name, sizeof ( disk_dev_name) - 1);
+      } else {
+         strncpy ( disk_dev_name, dev_name, sizeof ( disk_dev_name) - 1);
+	  }
    } else {
       ret = -LVM_EPV_GET_SIZE_LVM_DIR_CACHE;
       goto pv_get_size_end;
    }
-
-   memset ( disk_dev_name, 0, sizeof ( disk_dev_name));
-   strncpy ( disk_dev_name, dir_cache[i].dev_name, sizeof ( disk_dev_name) - 1);
 
    first = 1;
    if ( ( pv_handle = open ( disk_dev_name, O_RDONLY)) == -1) {
--- LVM/0.9/tools/lib/Makefile.in.bluca.orig	Sun Nov 12 19:52:12 2000
+++ LVM/0.9/tools/lib/Makefile.in	Sun Nov 26 19:49:22 2000
@@ -32,9 +32,11 @@
 include ../tools_and_lib.make.tmpl
 
 ARCHIVE = liblvm.a
+SOV = liblvm.so.0.9.0
+SOM = liblvm.so.0.9
 SO = liblvm.so
 
-ALL_RM = $(ALL_OBJECTS) $(ARCHIVE) $(SO)
+ALL_RM = $(ALL_OBJECTS) $(ARCHIVE) $(SO) $(SOM) $(SOV)
 
 all_this: $(ARCHIVE) $(SO) Makefile
 	@echo ""
@@ -43,15 +45,17 @@
 
 install_this:
 	@echo "*** Installing $(ARCHIVE) and $(SO) in ${prefix}/lib ***"
-	@rm -f ${libdir}/${SO} ${libdir}/$(ARCHIVE);
+	@rm -f ${libdir}/${SO} ${libdir}/${SOV} ${libdir}/${SOM} ${libdir}/$(ARCHIVE);
 	@INSTALL@ -d ${libdir}
-	@INSTALL@ $(ARCHIVE) $(SO) ${libdir}
+	@INSTALL@ $(ARCHIVE) $(SOV) ${libdir}
 	chmod 444 ${libdir}/$(ARCHIVE)
-	chmod 555 ${libdir}/$(SO)
+	chmod 555 ${libdir}/$(SOV)
+	ln -s $(SOV) ${libdir}/${SO}
+	ln -s $(SOV) ${libdir}/${SOM}
 
 remove_this:
 	@echo "*** Removing $(ARCHIVE) and $(SO) in ${prefix}/lib ***"
-	@rm -f ${libdir}/${SO} ${libdir}/$(ARCHIVE);
+	@rm -f ${libdir}/${SO} ${libdir}/${SOV} ${libdir}/${SOM} ${libdir}/$(ARCHIVE);
 
 $(ALL_SOURCES):	liblvm.h $(OTHER_DEP)
 
@@ -64,7 +68,9 @@
 	ranlib $@
 
 $(SO):	$(ALL_OBJECTS)
-	ld -shared -o $(SO) $(ALL_OBJECTS)
+	gcc -shared -Wl,-soname,$(SOM) -o $(SOV) $(ALL_OBJECTS)
+	ln -sf $(SOV) $(SOM)
+	ln -sf $(SOV) $(SO)
 
 clean_this:
 	rm -f $(ALL_RM)
--- LVM/0.9/tools/lib/vg_read_from_pv.c.bluca.orig	Mon Nov 13 01:26:33 2000
+++ LVM/0.9/tools/lib/vg_read_from_pv.c	Thu Dec  7 11:38:54 2000
@@ -45,7 +45,9 @@
       goto vg_read_from_pv_end;
    }
 
-   if ( pv_read ( pv_name, &pv_this_ptr, NULL) == 0) {
+   if ( ( ret = pv_read ( pv_name, &pv_this_ptr, NULL)) == 0 ||
+	   ret == -LVM_EPV_READ_MD_DEVICE ||
+	   ret == -LVM_EPV_READ_PV_EXPORTED) {
       /* read the VG info */
       if ( ( pv_handle = open ( pv_name, O_RDONLY)) == -1)
          ret = -LVM_EVG_READ_OPEN;
@@ -53,6 +55,7 @@
                 pv_this_ptr->vg_on_disk.base) ret = -LVM_EVG_READ_LSEEK;
       else if ( read ( pv_handle, &vg_this, sizeof ( vg_this)) != \
                 sizeof ( vg_this)) ret = -LVM_EVG_READ_READ;
+      else ret = 0;
       if ( pv_handle != -1) close ( pv_handle);
    
       if ( ret == 0) {
--- LVM/0.9/tools/lib/liblvm.h.bluca.orig	Tue Nov 14 23:20:24 2000
+++ LVM/0.9/tools/lib/liblvm.h	Thu Dec  7 13:06:39 2000
@@ -108,6 +108,7 @@
 #define	LVMTAB_DIR              "/etc/lvmtab.d"	/* storage dir VG data */
 #define	LVMTAB_MINSIZE   ( sizeof ( vg_t) + sizeof ( lv_t) + sizeof ( pv_t))
 #define	LVM_DEV                 "/dev/lvm"
+#define	DEVFS_DEV               ".devfsd"
 #define	VG_BACKUP_DIR           "/etc/lvmconf"
 #define	DISK_NAME_LEN		8
 #define	LV_MIN_NAME_LEN		5
--- LVM/0.9/tools/lib/pv_read_uuidlist.c.bluca.orig	Mon Nov 20 03:14:51 2000
+++ LVM/0.9/tools/lib/pv_read_uuidlist.c	Thu Dec  7 11:44:16 2000
@@ -61,7 +61,9 @@
         pv_uuidlist == NULL) {
       ret = -LVM_EPARAM;
    } else {
-      if ( ( ret = pv_read ( pv_name, &pv_this_ptr, NULL)) == 0) {
+      if ( ( ret = pv_read ( pv_name, &pv_this_ptr, NULL)) == 0 ||
+              ret == -LVM_EPV_READ_MD_DEVICE ||
+              ret == -LVM_EPV_READ_PV_EXPORTED) {
          if ( ( pv_handle = open ( pv_name, O_RDONLY)) == -1)
             ret = -LVM_EPV_READ_UUIDLIST_OPEN;
          else if ( lseek ( pv_handle,
@@ -89,6 +91,7 @@
                         memset ( ptr, 0, NAME_LEN);
                      }
                   }
+		  ret = 0;
                }
                for ( i = 0; i < ABS_MAX_PV - 1; i++) {
                   ptr = this_pv_uuidlist + i * NAME_LEN;
--- LVM/0.9/tools/lib/vg_remove_dir_and_group_and_nodes.c.bluca.orig	Mon Nov 13 01:20:11 2000
+++ LVM/0.9/tools/lib/vg_remove_dir_and_group_and_nodes.c	Thu Dec  7 13:24:58 2000
@@ -43,11 +43,14 @@
    debug_enter ( "vg_remove_dir_and_group_and_nodes -- CALLED\n");
 #endif
 
-   if ( vg_name != NULL && vg_check_name ( vg_name) == 0) {
+   if ( vg_name == NULL || vg_check_name ( vg_name) < 0) ret = -LVM_EPARAM;
+   /* should be a warning, but i would have to catch it */
+   else if ( access ( LVM_DIR_PREFIX "/" DEVFS_DEV, F_OK) == 0 ) ret = 0;
+   else {
       /* remove the volume group directory */
       sprintf ( buffer, LVM_DIR_PREFIX "%s%c", vg_name, 0);
       ret = lvm_remove_recursive ( buffer);
-   } else ret = -LVM_EPARAM;
+   }
 
 #ifdef DEBUG
    debug_leave ( "vg_remove_dir_and_group_and_nodes -- LEAVING with ret: %d\n",