XFS and nobarriers on Intel SSD

[Richard Bade <hitrich@xxxxxxxxx>]

Hi Everyone,

I have a question about nobarriers. In the XFS FAQ it looks like the recommendation is that if you have a Battery Backed raid controller you should set nobarriers for performance reasons.

Our LSI card doesnât have battery backed cache as itâs configured in HBA mode (IT) rather than Raid (IR). Our Intel s3710 SSDâs do have a capacitor backed cache though.

So is it recommended that barriers are turned off as the drive has a safe cache (I am confident that the cache will write out to disk on power failure)?

The reason I am asking about this is that we are seeing some significant I/O delays on the disks causing a âSCSI Task Abortâ from the OS. This seems to be triggered by the drive receiving a âSynchronize cache commandâ.

My current thinking is that setting no barriers will stop the drive receiving a sync command and therefore stop the I/O delay associated with it.

This is happening on our Ceph storage cluster. For those not familiar with Ceph, it uses XFS as the underlying filesystem for the object stores.

Has anyone else encountered this issue?

Any info or suggestions about this would be appreciated.Â

Regards,

Richard