[Gluster-users] Replication delay

[Pranith Kumar Karampuri]

Vijay,
     But it seems like self-heal's fd is able to perform 'writes'. Shouldn't it be uniform if it is the problem with xfs?

Pranith
----- Original Message -----
> From: "Vijay Bellur" <vbellur at redhat.com>
> To: "Fabio Rosati" <fabio.rosati at geminformatica.it>, "Pranith Kumar Karampuri" <pkarampu at redhat.com>
> Cc: "Gluster-users at gluster.org List" <gluster-users at gluster.org>
> Sent: Saturday, January 25, 2014 1:23:52 PM
> Subject: Re: [Gluster-users] Replication delay
> 
> 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
> 
>