* Re: mkfs.xfs cannot make sector size 64 KiB?
2007-04-29 16:25 ` mkfs.xfs cannot make sector size 64 KiB? Justin Piszcz
@ 2007-04-29 17:22 ` Eric Sandeen
0 siblings, 0 replies; 2+ messages in thread
From: Eric Sandeen @ 2007-04-29 17:22 UTC (permalink / raw)
To: Justin Piszcz; +Cc: xfs, linux-kernel
Justin Piszcz wrote:
> Adding LKML to cc list.
>
> On Sun, 29 Apr 2007, Justin Piszcz wrote:
>
>>> From the manpage:
>>
>> -b Block size options.
>>
>> This option specifies the fundamental block size of the
>> filesys-
>> tem. The valid suboptions are: log=value and
>> size=value; only
>> one can be supplied. The block size is specified
>> either as a
>> base two logarithm value with log=, or in bytes with
>> size=. The
>> default value is 4096 bytes (4 KiB), the minimum is 512,
>> and the
>> maximum is 65536 (64 KiB). XFS on Linux currently only
>> supports
>> pagesize or smaller blocks.
>>
>> The maximum size is 64 KiB, yet it seems only up to 32 KiB is valid?
above is block size, not sector size
>> I am running x86_64.
then you are limited to blocks (and therefore sectors) <= page size, so
<= 4096.
You can -mkfs- something bigger, but you won't be able to mount it.
>> $ uname -m
>> x86_64
>>
>>
>> p34:~# mkfs.xfs -b size=512 /dev/md3
>> mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
>> mkfs.xfs: Use the -f option to force overwrite.
>> p34:~# mkfs.xfs -b size=4096 /dev/md3
>> mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
>> mkfs.xfs: Use the -f option to force overwrite.
>> p34:~# mkfs.xfs -b size=8192 /dev/md3
>> mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
>> mkfs.xfs: Use the -f option to force overwrite.
>> p34:~# mkfs.xfs -b size=16384 /dev/md3
>> mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
>> mkfs.xfs: Use the -f option to force overwrite.
>> p34:~# mkfs.xfs -b size=32768 /dev/md3
>> mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
>> mkfs.xfs: Use the -f option to force overwrite.
>> p34:~# mkfs.xfs -b size=65536 /dev/md3
>> illegal sector size 65536
This is mkfs.xfs trying to be smart about making larger "sectors" (==
blocksize) on an md device, so that it does not switch the size of the
IO requests between data & metadata, slowing things down significantly.
however,
-s Sector size options.
This option specifies the fundamental sector size of
the filesystem. The
valid suboptions are: log=value and size=value; only one
can be supplied.
The sector size is specified either as a base two
logarithm value with
log=, or in bytes with size=. The default value is 512
bytes. The minimum
value for sector size is 512; the maximum is 32768 (32
KiB). The sector
size must be a power of 2 size and cannot be made larger
than the filesys-
tem block size.
looks like a buglet where it is trying to make a block == sector == 64k,
but sectors are limited to 32.
But this is not what you want anyway, assuming you want to actually
*mount* your new filesystem on x86_64. Just make take default
blocksize (4k) and be happy.
>> Usage: mkfs.xfs
>> /* blocksize */ [-b log=n|size=num]
>> /* data subvol */ [-d agcount=n,agsize=n,file,name=xxx,size=num,
>> (sunit=value,swidth=value|su=num,sw=num),
>> sectlog=n|sectsize=num,unwritten=0|1]
>> /* inode size */ [-i
>> log=n|perblock=n|size=num,maxpct=n,attr=0|1|2]
>> /* log subvol */ [-l
>> agnum=n,internal,size=num,logdev=xxx,version=n
>> sunit=value|su=num,sectlog=n|sectsize=num]
>> /* label */ [-L label (maximum 12 characters)]
>> /* naming */ [-n log=n|size=num,version=n]
>> /* prototype file */ [-p fname]
>> /* quiet */ [-q]
>> /* realtime subvol */ [-r extsize=num,size=num,rtdev=xxx]
>> /* sectorsize */ [-s log=n|size=num]
>> /* version */ [-V]
>> devicename
>> <devicename> is required unless -d name=xxx is given.
>> <num> is xxx (bytes), xxxs (sectors), xxxb (fs blocks), xxxk (xxx KiB),
>> xxxm (xxx MiB), xxxg (xxx GiB), xxxt (xxx TiB) or xxxp (xxx PiB).
>> <value> is xxx (512 byte blocks).
>> p34:~#
>>
>> Unless, the page size is not <= 64 for x86_64?
it's not, but that's not why this broke.
-Eric
>> Justin.
>>
>>
>
>
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