Re: [ClusterLabs] Antw: Re: [Slightly OT] OCFS2 over LVM

2015-08-25 Thread Digimer
On 25/08/15 04:45 AM, Ulrich Windl wrote:
 Digimer li...@alteeve.ca schrieb am 24.08.2015 um 18:20 in Nachricht
 55db4453.10...@alteeve.ca:
 [...]
 Using a pair of nodes with a traditional file system exported by NFS and
 made accessible by a floating (virtual) IP address gives you redundancy
 without incurring the complexity and performance overhead of cluster
 locking. Also, you won't need clvmd either. The trade-off through is
 that if/when the primary fails, the nfs daemon will appear to restart to
 the users and that may require a reconnection (not sure, I use nfs
 sparingly).
 
 But that's a cheap trick: You say don't provide HA-storage (CFS), but use 
 existing one (NFS). How do you build a HA-NFS server? You need another 
 cluster. Not everybody has that many nodes available.

DRBD in single-primary will do the job just fine. Recovery is simply a
matter of; fence - promote to primary - mount - start nfs - take
virtual IP, done.

Only 2-nodes needed. This is a common setup.

 Generally speaking, I recommend always avoiding cluster FSes unless
 they're really required. I say this as a person who uses gfs2 in every
 cluster I build, but I do so carefully and in limited uses. In my case,
 gfs2 backs ISOs and XML definition files for VMs, things that change
 rarely so cluster locking overhead is all but a non-issue, and I have to
 have DLM for clustered LVM anyway, so I've already incurred the
 complexity costs so hey, why not.

 -- 
 Digimer
 Papers and Projects: https://alteeve.ca/w/ 
 What if the cure for cancer is trapped in the mind of a person without
 access to education?

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-- 
Digimer
Papers and Projects: https://alteeve.ca/w/
What if the cure for cancer is trapped in the mind of a person without
access to education?

___
Users mailing list: Users@clusterlabs.org
http://clusterlabs.org/mailman/listinfo/users

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[ClusterLabs] Antw: Re: [Slightly OT] OCFS2 over LVM

2015-08-25 Thread Ulrich Windl
 Digimer li...@alteeve.ca schrieb am 24.08.2015 um 18:20 in Nachricht
55db4453.10...@alteeve.ca:
[...]
 Using a pair of nodes with a traditional file system exported by NFS and
 made accessible by a floating (virtual) IP address gives you redundancy
 without incurring the complexity and performance overhead of cluster
 locking. Also, you won't need clvmd either. The trade-off through is
 that if/when the primary fails, the nfs daemon will appear to restart to
 the users and that may require a reconnection (not sure, I use nfs
 sparingly).

But that's a cheap trick: You say don't provide HA-storage (CFS), but use 
existing one (NFS). How do you build a HA-NFS server? You need another cluster. 
Not everybody has that many nodes available.

 
 Generally speaking, I recommend always avoiding cluster FSes unless
 they're really required. I say this as a person who uses gfs2 in every
 cluster I build, but I do so carefully and in limited uses. In my case,
 gfs2 backs ISOs and XML definition files for VMs, things that change
 rarely so cluster locking overhead is all but a non-issue, and I have to
 have DLM for clustered LVM anyway, so I've already incurred the
 complexity costs so hey, why not.
 
 -- 
 Digimer
 Papers and Projects: https://alteeve.ca/w/ 
 What if the cure for cancer is trapped in the mind of a person without
 access to education?
 
 ___
 Users mailing list: Users@clusterlabs.org 
 http://clusterlabs.org/mailman/listinfo/users 
 
 Project Home: http://www.clusterlabs.org 
 Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf 
 Bugs: http://bugs.clusterlabs.org 





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Project Home: http://www.clusterlabs.org
Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
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