[Users] Creation of preallocated disk with Gluster replication

[Vijay Bellur]

Adding gluster-users.

On 01/02/2014 08:50 PM, gregoire.leroy at retenodus.net wrote:
> Hello,
>
> I have a Gluster volume in distributed/replicated mode. I have 2 hosts.
> When I try to create a VM with a preallocated disk, it uses 100% of the
> available CPU and bandwidth (I have 1 Gigabit network card).
> The result is I can't even create a preallocated disk because the engine
> detects a network failure.
>
> I get that kind of messages in /var/log/messages :
> "
> Jan  2 14:13:54 localhost sanlock[3811]: 2014-01-02 14:13:54+0100 167737
> [3811]: s4 kill 21114 sig 15 count 1
> Jan  2 14:13:54 localhost wdmd[3800]: test failed rem 51 now 167737 ping
> 167718 close 167728 renewal 167657 expire 167737 client 3811
> sanlock_ef4978d6-5711-4e01-a0ec-7ffbd9     cdbe5d:1
> "
>
> And that in the Ovirt Gui :
> "
> 2014-janv.-02, 15:35 Operation Add-Disk failed to complete.
> 2014-janv.-02, 15:35 Storage Pool Manager runs on Host HOST2 (Address:
> X.X.X.X).
> 2014-janv.-02, 15:35 Invalid status on Data Center GlusterSewan. Setting
> Data Center status to Non Responsive (On host HOST2, Error: done).
> 2014-janv.-02, 15:35 State was set to Up for host HOST2.
> 2014-janv.-02, 15:33 Used Network resources of host HOST2 [98%] exceeded
> defined threshold [95%].
> 2014-janv.-02, 15:33 Add-Disk operation of test_Disk1 was initiated on
> VM test by admin at internal.
>
> I understand that the creation of a 10 Go disk image generates a lot of
> traffic, but is there a way to limit it so that it doesn't have an
> impact on the production ? Furthermore, Why does it use so much CPU
> ressources ? I can see on my monitoring graph a big peak of CPU usage
> when I launched the operation (probably until 100%).

Do you happen to notice what is consuming CPU? Since the same cluster 
does both virtualization and storage, a GigE network might get saturated 
very quickly. Is it possible to separate out the management and 
data/gluster traffic in this setup?

Regards,
Vijay