[Gluster-users] Replication delay

[Vijay Bellur]

On 01/24/2014 09:24 PM, Fabio Rosati wrote:

>
>
> The block size is the same, 4096 bytes.
> I did some other investigation and it seems the problem happens only with VM disk images internally formatted with a blocksize of 1024 bytes. There are no problems with disk images formatted with a block size on 4096 bytes. Anyway, I don't know if this is a coincidence.
>
> Do you think this could be the origin of the problem? If so, how can I solve it?
> In the links posted by Vijay someone suggests to start the VM with cache != none but this will prevent live migration, AFAIK.
> Another solution may be to recreate the volume backing it with XFS partitions formatted with a different block size (smaller? 1024 bytes?), this would be a painful option, but if this will solve the problem, I go for it.
>

A lower sector size (512) for xfs has been observed to be useful in 
overcoming this problem.

Another solution might be to use logical_block_size=4096 option as 
referred here [1].

-Vijay

[1] https://bugzilla.redhat.com/show_bug.cgi?id=997839#c7