[Gluster-users] Mounting gluster volume from fstab at boot - Specifying multiple server nodes

[Jon Swanson]

Hi Tejas,
Thanks for the response.

We have a cluster consisting of 6 machines, configured as 2 distributes 
over 3 nodes, which are then replicated.

A-|\              /|-D
B-|-Dist      Dist-|-E
C-|/ |         |  \|-F
      |         |
      |         |
      .Replicate.

In theory, we can lose a few different nodes here without any 
interruption of service. The client, let's call it 'Z', has an fstab 
entry to mount the gluster volume depicted above from 'A'. As soon as 
the client connects, it gets the information for the entire volume of 
course, so if 'A' goes down at any point after that there are no 
problems, everything is transparent to the client.

If 'A' happens to be down when 'Z' boots however, it will never make any 
connection.

It feels like there should be a way to specify multiple hosts at the 
initial mount time, as as parsed through fstab, without having to 
maintain a volume definition on every single client.

There's a big chance i'm misunderstanding something here, and 
wholeheartedly welcome any corrections.

Thanks,
  jon



Note: one solution is to just have multiple lines in the fstab. This 
works but is very hacking and generates notifications in all cases:
NodeA         /mnt glusterfs 
rw,allow_other,default_permissions,max_read=131072 0 0
NodeD         /mnt glusterfs 
rw,allow_other,default_permissions,max_read=131072 0 0


Note2: This is a /very/ limited case, and quite easy to diagnose so is 
in no way a show stopper.


On 03/15/2010 04:36 PM, Tejas N. Bhise wrote:
> Jon,
>
> Why not just use replication ? and distribute over the replicated setup ? you can stack it up like that.
>
> Regards,
> Tejas.
> ----- Original Message -----
> From: "Jon Swanson"<jswanson at valuecommerce.co.jp>
> To: gluster-users at gluster.org
> Sent: Monday, March 15, 2010 12:54:55 PM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
> Subject: [Gluster-users] Mounting gluster volume from fstab at boot - Specifying multiple server nodes
>
>
> Hello. glusterfs is flat out awesome.
>
> Just had a quick question about mounting a volume via fstab at boot time
> that did not seem to be answered
> here:http://www.gluster.com/community/documentation/index.php/Mounting_a_GlusterFS_Volume
>
> I'd like to be able to specify multiple nodes at boot time, so if the
> volume is spanned across Nodes A,B,C,D, and A goes down, the system will
> still automatically mount the volume from B. It seems like you could do
> that relatively easily referencing a volume file on the client.
>
> I would like to avoid maintaining separate volume files on each client
> if at all possible though.
>
>
> Is there a syntax for providing an fstab line for a gluster mount that
> will allow the gluster client to try multiple hosts in the event one is
> down?
>
>
> Thanks,
>   jon
>
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