[Linux-cluster] [clvm] Volume group for uuid not found

[Abraham Alawi]

On 2/02/2010, at 11:31 AM, Gordan Bobic wrote:

> Abraham Alawi wrote:
>> On 2/02/2010, at 5:21 AM, Gordan Bobic wrote:
>>> AlannY wrote:
>>>> On Mon, Feb 01, 2010 at 03:34:18PM +0000, Christine Caulfield wrote:
>>>>> Is it really two different devices ? If so then clvmd will not work.
>>>>> It needs the same view of storage on all systems. Not necessarily
>>>>> the same names, but definitely the same actual storage.
>>>> So, should I use DRBD with clvm for data mirroring on both nodes?
>>> You could, indeed, use DRBD. Or you could cross-export the block devices with iSCSI (or ATAoE) and have them connected to all the nodes that way. I guess it depends on whether you prefer to use DRBD or CLVM. My preference is for DRBD, but don't let that bias your decision. :)
>>> 
>>> Gordan
>>> 
>> I reckon GNBD will be a better solution in your case, DRBD is more
>> suitable for non-cluster file systems (e.g. ext3, xfs .. ) in case
>> of active-passive
> 
> DRBD is specifically designed to also work in active-active mode. I've been running shared root GFS clusters on DRBD for years. DRBD is singularly _THE_ best solution for network RAID1, _especially_ in active-active mode with a clustered file system on top. It also handles resyncing after outages much more gracefully and transparently than other similar solutions.
> 
> Gordan
> 

Yes, it does work in active-active but DRBD people themselves don't recommend running it in production active-active under cluster file system, I quote from their website:
"DRBD's primary-primary mode with a shared disk file system (GFS, OCFS2). These systems are very sensitive to failures of the replication network. Currently we cannot generally recommend this for production use."
http://www.drbd.org/home/mirroring/

In terms of production solution I reckon GNBD is designed more specifically for that purpose. I'm glad to know that DRBD is running well for you under GFS, honestly I have never tried this setup, it's worthwhile trying though. 

Cheers,

  -- Abraham


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Abraham Alawi

Unix/Linux Systems Administrator
Science IT
University of Auckland
e: a.alawi at auckland.ac.nz
p: +64-9-373 7599, ext#: 87572

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