[Gluster-users] anyone using glusterfs as openstack cinder/nova storage?

[Vijay Bellur]

On 12/30/2014 08:35 PM, Zhu,Chao wrote:
> hi,all,
> Â  Â  We are using glusterfs 3.5 on top of centos 6.5 with openstack
> version I;
> Â  Â  We have about ~50 nodes as storage server, and 300 nova computing
> nodes;Â

What version of 3.5.x is in use here? Are you using the fuse client or 
libgfapi to access the gluster servers?

> Â  Â  One questoin we have is:
> Â  Â  When I add new servers into the storage pool, and I will have to
> do re-balance for the glusterfs cluster,(first fix-layout, and then
> migrate data);
> Â  Â  As for the VMs are always running and the file on glusterfs is
> always opened, does glusterfs support online file migration?( with vm
> continue running, aka, open file migration supported?)
> Â  Â  From the documentation it looks like it is ok, but in our
> environment, when we does the rebalance, lots of vm got disk read-only;
> Which is very bad;

Do you observe any errors in the gluster client log files when vm disks 
go read-only? It would also be useful if you could file a bug report 
with as many details if you notice a problem consistently. Some 
guidelines for reporting a bug can be found here [1].


>
> Â  Â  A similar question is, when I have say 3 replica, one node goes
> down for HW maintenance and when it comes back online, How does it do
> the re-sync? As all the VMs disks are continuously being modified, and
> each VM disk is pretty big(usually 5gb-40gb); It would be nightmare to
> re-sync the whole brick replica?
>

self-heal makes use of a rsync like algorithm to synchronize files. Only 
relevant regions of a file do get copied over the network for 
synchronization of data.


Regards,
Vijay

[1] 
http://www.gluster.org/community/documentation/index.php/Bug_reporting_guidelines