Strange ARC usage

[roedie]

I've noticed my ARC size often exceeds the maximum size. When I reboot the ARC stays within normal bounds for about 2 weeks, and after that it starts allocating more than the max.

Also, at the same moment this starts, disk utilisation and disk IO-wait go up.

This happens with zfs 0.6.4.1, all data is server over NFS.

[behlendorf]

@roedie the recently released 0.6.4.2 tag has some patches which should help with this. Specifically one of the following depending on your kernel version.

• Improve metadata shrinker performance on pre-3.1 kernels Add zfs_sb_prune_compat() function #3501, and
• Linux 3.12 compat: NUMA-aware per-superblock shrinker

https://github.com/zfsonlinux/zfs/releases/tag/zfs-0.6.4.2

[roedie]

@behlendorf Thanks for your answer. But now I'm a bit stuck between a rock and a hard place. Unless #3445 is also fixed by 0.6.4.2. Last time I upgraded to 0.6.4.1 or 544f71 I got system hangs within a couple of days.

[gmelikov]

Close as stale.

If it's actual - feel free to reopen.