[Gluster-users] Self heal with VM Storage

[Tejas N. Bhise]

Thanks, that will help reproduce internally. 

Regards,
Tejas.
----- Original Message -----
From: "Justice London" <jlondon at lawinfo.com>
To: "Tejas N. Bhise" <tejas at gluster.com>
Cc: gluster-users at gluster.org
Sent: Friday, April 16, 2010 9:03:50 PM
Subject: RE: [Gluster-users] Self heal with VM Storage

After the self heal finishes it sort of works. Usually this destroys InnoDB
if you're running a database. Most often, though, it also causes some
libraries and similar to not be properly read in by the VM guest which means
you have to reboot it to fix for this. It should be fairly easy to
reproduce... just shut down a storage brick (any configuration... it doesn't
seem to matter). Make sure of course that you have a running VM guest (KVM,
etc) using the gluster mount. You'll then turn off(unplug, etc.) one of the
storage bricks and wait a few minutes... then re-enable it.

Justice London
jlondon at lawinfo.com

-----Original Message-----
From: Tejas N. Bhise [mailto:tejas at gluster.com] 
Sent: Thursday, April 15, 2010 7:41 PM
To: Justice London
Cc: gluster-users at gluster.org
Subject: Re: [Gluster-users] Self heal with VM Storage

Justice,

Thanks for the description. So, does this mean 
that after the self heal is over after some time, 
the guest starts to work fine ?

We will reproduce this inhouse and get back.

Regards,
Tejas.
----- Original Message -----
From: "Justice London" <jlondon at lawinfo.com>
To: "Tejas N. Bhise" <tejas at gluster.com>
Cc: gluster-users at gluster.org
Sent: Friday, April 16, 2010 1:18:36 AM
Subject: RE: [Gluster-users] Self heal with VM Storage

Okay, but what happens on a brick shutting down and being added back to the
cluster? This would be after some live data has been written to the other
bricks.

>From what I was seeing access to the file is locked. Is this not the case?
If file access is being locked it will obviously cause issues for anything
trying to read/write to the guest at the time.

Justice London
jlondon at lawinfo.com

-----Original Message-----
From: Tejas N. Bhise [mailto:tejas at gluster.com] 
Sent: Thursday, April 15, 2010 12:33 PM
To: Justice London
Cc: gluster-users at gluster.org
Subject: Re: [Gluster-users] Self heal with VM Storage

Justice,

>From posts from the community on this user list, I know 
that there are folks that run hundreds of VMs out of 
gluster. 

So it's probably more about the data usage than just a 
generic viability statement as you made in your post.

Gluster does not support databases, though many people
use them on gluster without much problem. 

Please let me know if you see some problem with unstructured 
file data on VMs. I would be happy to help debug that problem.

Regards,
Tejas.


----- Original Message -----
From: "Justice London" <jlondon at lawinfo.com>
To: gluster-users at gluster.org
Sent: Friday, April 16, 2010 12:52:19 AM
Subject: [Gluster-users] Self heal with VM Storage

I am running gluster as a storage backend for VM storage (KVM guests). If
one of the bricks is taken offline (even for an instant), on bringing it
back up it runs the metadata check. This causes the guest to both stop
responding until the check finishes and also to ruin data that was in
process (sql data for instance). I'm guessing the file is being locked while
checked. Is there any way to fix for this? Without being able to fix for
this, I'm not certain how viable gluster will be, or can be for VM storage.

 

Justice London

jlondon at lawinfo.com


_______________________________________________
Gluster-users mailing list
Gluster-users at gluster.org
http://gluster.org/cgi-bin/mailman/listinfo/gluster-users