Re: suddenly slow writes on XFS Filesystem

Stefan Priebe - Profihost AG
2012-05-07T07:22:45Z

>> # vmstat
> "vmstat 5", not vmstat 5 times.... :/
oh sorry. Sadly the rsync processes do not run right know i've to kill
them. Is the output still usable?
# vmstat 5
procs -----------memory---------- ---swap-- -----io---- -system--
----cpu----
r b swpd free buff cache si so bi bo in cs us sy
id wa
0 1 0 5582136 48 5849956 0 0 176 394 34 54 1
16 82 1
0 1 0 5552180 48 5854280 0 0 2493 2496 3079 2172 1
4 86 9
3 2 0 5601308 48 5857672 0 0 1098 28043 5150 1913 0
10 73 17
0 2 0 5595360 48 5863180 0 0 1098 14336 3945 1897 0
8 69 22
3 2 0 5594088 48 5865280 0 0 432 15897 4209 2366 0
8 71 21
0 2 0 5591068 48 5868940 0 0 854 10989 3519 2107 0
7 70 23
1 1 0 5592004 48 5869872 0 0 180 7886 3605 2436 0
3 76 22

>> /dev/sdb1 4,6T 4,3T 310G 94% /mnt
> Well, you've probably badly fragmented the free space you have. what
> does the 'xfs_db -r -c freesp <dev>' command tell you?

from to extents blocks pct
1 1 942737 942737 0,87
2 3 671860 1590480 1,47
4 7 461268 2416025 2,23
8 15 1350517 18043063 16,67
16 31 111254 2547581 2,35
32 63 192032 9039799 8,35
64 127 33026 3317194 3,07
128 255 14254 2665812 2,46
256 511 12516 4631200 4,28
512 1023 6942 5031081 4,65
1024 2047 4622 6893270 6,37
2048 4095 3268 9412271 8,70
4096 8191 2135 12716435 11,75
8192 16383 338 3974884 3,67
16384 32767 311 7018658 6,49
32768 65535 105 4511372 4,17
65536 131071 29 2577756 2,38
131072 262143 8 1339796 1,24
262144 524287 10 3950416 3,65
524288 1048575 4 2580085 2,38
1048576 2097151 2 3028028 2,80

>>>> #~ df -i
>>>> /dev/sdb1 4875737052 4659318044 216419008 96% /mnt
>>> You have 4.6 *billion* inodes in your filesystem?
>> Yes - it backups around 100 servers with a lot of files.
i rechecked this and it seems i sadly copied the wrong output ;-( sorry
for that.

Here is the correct one:
#~ df -i
/dev/sdb1 975173568 95212355 879961213 10% /mnt

Stefan