[Gluster-users] Fwd: Re: Use of xfs_fsr

[Tobias Reinhard]

Am 30.08.2013 21:40, schrieb Robert Hajime Lanning:
> On 08/29/13 10:50, Tobias Reinhard wrote:
>> Hi!
>>
>> I would like to defrag the XFS partition on which my glusterfs brick is.
>> Normally no program cares about xfs_fsr.
>>
>> Just to make sure: is it "safe" to run xfs_fsr on a glusterfs brick
>> while everything is online or does any part of glusterfs gets confused?
>>
>> I have a two node replicated volume (if that is relevant) running
>> glusterfs 3.4
>
> The GlusterFS server is all userspace. So, as long as you are not
> taking the underlying (XFS) filesystem offline, it won't care one bit.
>
> Though you might see a performance hit for anything doing I/O to the
> filesystem in question.
>
> Do you run your filesystems near full capacity? (wondering why you
> need a defrag.)
>
The FS is 70% full (on a 3.5TB parition).

I placed some KVM images on the cluster in QED format. It seems they get
fragmented as they grow.

Whenever a node goes offline and gets online again the self-healing is
nearly killing the cluster. The images are only read at 15mb/s.

Even throtteling down the self-heal only helps a little.

I'll try if a defrag solves this issue.

Tobias