[Gluster-users] Writing to distributed (non-replicated) volume with failed nodes

[Leonid Isaev]

Hi,

On Thu, Oct 08, 2015 at 08:15:42AM -0400, Susant Palai wrote:
> If the file creation hashes to the brick which is down, then it fails with
> ENOENT.

OK, thanks for the explanation. But is there any way (some dht configuration,
perhaps?) to force this hashing to include only online bricks?

Otherwise the situation is rather odd: no matter how big a distributed volume
is, it's only as robust as the weakest node, because some file operations will
always fail...

Thanks,
L.

> ----- Original Message -----
> From: "Leonid Isaev" <leonid.isaev at jila.colorado.edu>
> To: gluster-users at gluster.org
> Sent: Thursday, 8 October, 2015 7:54:07 AM
> Subject: [Gluster-users] Writing to distributed (non-replicated) volume with	failed nodes
> 
> Hi,
> 
> 	I have an 8-node trusted pool with a distributed, non-replicated volume
> The bricks are located only on 2 machines (2 bricks per node), so there are 6
> dummy" nodes. Everything is working great until one of the brick-arrying nodes
> experiences a power outage.
> 	In this case, I can still mount the volume after a timeout (there is
> plenty of servers to ask for metadata, after all) and read files from there,
> but whenever I try to create a random-named file (e.g. running touch
> /mnt/.lock-${RANDOM}${RANDOM}) this succeeds only sometimes, but often fails
> with "no such file or directory". I understand that error if I were touching
> files that already exist on the offline node (but invisible with the degraded
> volume), but these are new random files which never existed before.
> 	So, why does writing to the online bricks fail, and what can I do to
> enable it? The machines run fully up-to-date Fedora 22 and ArchLinux with
> gluster 3.7.4. I tried to look for similar problems on this ML, but haven't
> found anything related, sorry if I missed something.
> 
> Thanks!
> L.
> 
> -- 
> Leonid Isaev
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-- 
Leonid Isaev
GPG fingerprints: DA92 034D B4A8 EC51 7EA6  20DF 9291 EE8A 043C B8C4
                  C0DF 20D0 C075 C3F1 E1BE  775A A7AE F6CB 164B 5A6D