[Gluster-users] Gluster 3.2.0 and ucarp not working

[Mohit Anchlia]

On Wed, Jun 8, 2011 at 1:37 PM, Joshua Baker-LePain <jlb17 at duke.edu> wrote:
> On Wed, 8 Jun 2011 at 1:18pm, Mohit Anchlia wrote
>
>>>> Prior to this thread, I thought the best method was to use ucarp on the
>>>> servers and mount using the ucarp address.  If that won't work right (I
>>>> haven't had time to fully test my setup yet), then I need to find
>>>> another
>>>> way.  I don't run DNS on my cluster, so that solution is out.  As far as
>>>> I
>>>> can tell, the only other solution is to mount in rc.local, with logic to
>>>> detect a mount failure and go on to the next server.
>>>>
>>> ucarp should work so would the script at startup to check hosts before
>>> mounting.
>>
>> BTW: You need a virtual ip for ucarp
>
> As I said, that's what I'm doing now -- using the virtual IP address managed
> by ucarp in my fstab line.  But Craig Carl from Gluster told the OP in this
> thread specifically to mount using the real IP address of a server when
> using the GlusterFS client, *not* to use the ucarp VIP.
>
> So I'm officially confused.

I understand your confusion. On client side there are 2 concerns:

1) What if the server I am trying to mount to is down during reboot,
restart, remount etc.?
2) What if I mounted my file system using server A and server A goes down?

I think Craig was trying to address point 2. But you are worried about
point 1 correct?

Regarding point 1 - My suggestions are targeted towards point 1.

Regarding point 2 - If file system is already mounted using server A
and server A goes down then this will NOT impact the client mount.
Like Joe mentioned list of servers in the clusters are fetched from
server A during mount. After that if server A goes down it will still
have that list and knows the configuration of cluster. So in short
it's built in native glusterfs mount and provides HA on the client
side. However if you use NFS then you can solve that by using ucarp.

Clear as mud :)?


>
> --
> Joshua Baker-LePain
> QB3 Shared Cluster Sysadmin
> UCSF