Dave Chinner put forth on 10/11/2010 5:35 PM:
> On Mon, Oct 11, 2010 at 03:03:28PM +0100, James Braid wrote:
>> On Fri, Oct 8, 2010 at 23:51, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
>>> Sounds like fragmented free space. What is the output of:
>>> # xfs_db -r -c "freesp -s" <device>
>> # xfs_db -r -c "freesp -s" /dev/sdb
>> from to extents blocks pct
>> 1 1 2298052 2298052 40.52
>> 2 3 1568338 3337017 58.84
>> 4 7 8432 35716 0.63
>> 8 15 50 423 0.01
>> total free extents 3874872
>> total free blocks 5671208
>> average free extent size 1.46359
>> Which seems to say there are a few tiny pieces of free space
>> available? The files that were failing to be written were a few
>> hundred bytes in size.
> The error has nothing to do with the size of the files, but
> everything to do with being able to allocate more inodes. Inode
> allocation requires 4 contiguous blocks (for 256 byte inodes, more
> for larger inodes) with alignment constraints. That means when you
> run out of 8 block or larger free extents, inode allocation will
> start failing and you'll get ENOSPC being reported.
>> We haven't seen any errors so far today, but xfs_fsr ran over the
>> weekend, so perhaps I guess it's reorganized the filesystem.
> Only a little. xfs_fsr will not improve fragmented free space
> conditions (indeed, it normally fragments free space more). The only
> way to reduce the fragmentation of free space is to remove a
> significant amount of data and inodes from the filesystem...
Hay Dave, would a "backup/reformat/restore" help with free space
fragmentation in this case? If so, could/should the OP specify anything
during the mkfs.xfs reformat that may help alleviate or mitigate his
problem in the future?