Am 05.09.2014 um 14:30 schrieb Brian Foster:
> On Fri, Sep 05, 2014 at 11:47:29AM +0200, Stefan Priebe - Profihost AG wrote:
>> i have a backup system running 20TB of storage having 350 million files.
>> This was working fine for month.
>> But now the free space is so heavily fragmented that i only see the
>> kworker with 4x 100% CPU and write speed beeing very slow. 15TB of the
>> 20TB are in use.
>> Overall files are 350 Million - all in different directories. Max 5000
>> per dir.
>> Kernel is 3.10.53 and mount options are:
>> # xfs_db -r -c freesp /dev/sda1
>> from to extents blocks pct
>> 1 1 29484138 29484138 2,16
>> 2 3 16930134 39834672 2,92
>> 4 7 16169985 87877159 6,45
>> 8 15 78202543 999838327 73,41
>> 16 31 3562456 83746085 6,15
>> 32 63 2370812 102124143 7,50
>> 64 127 280885 18929867 1,39
>> 256 511 2 827 0,00
>> 512 1023 65 35092 0,00
>> 2048 4095 2 6561 0,00
>> 16384 32767 1 23951 0,00
>> Is there anything i can optimize? Or is it just a bad idea to do this
>> with XFS? Any other options? Maybe rsync options like --inplace /
> It's probably a good idea to include more information about your fs:
Generally sure but the problem itself is clear. If you look at the free
space allocation you see that free space is heavily fragmented.
But here you go:
- 3.10.53 vanilla
- xfs_repair version 3.1.11
- 16 cores
- /dev/sda1 /backup xfs
rw,noatime,nodiratime,attr2,inode64,logbufs=8,logbsize=256k,noquota 0 0
- Raid 10 with 1GB controller cache running in write back mode using 24
- no lvm
- no io waits
- xfs_info /serverbackup/
meta-data=/dev/sda1 isize=256 agcount=21,
= sectsz=512 attr=2
data = bsize=4096 blocks=5369232896, imaxpct=5
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=521728, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
> ... as well as what your typical workflow/dataset is for this fs. It
> seems like you have relatively small files (15TB used across 350m files
> is around 46k per file), yes?
Yes - most fo them are even smaller. And some files are > 5GB.
> If so, I wonder if something like the
> following commit introduced in 3.12 would help:
> 133eeb17 xfs: don't use speculative prealloc for small files