[Linux-cluster] Re: GFS, what's remaining

[Lars Marowsky-Bree]

On 2005-09-03T01:57:31, Daniel Phillips <phillips at istop.com> wrote:

> The only current users of dlms are cluster filesystems.  There are zero users 
> of the userspace dlm api. 

That is incorrect, and you're contradicting yourself here:

> What does have to be resolved is a common API for node management.  It is not 
> just cluster filesystems and their lock managers that have to interface to 
> node management.  Below the filesystem layer, cluster block devices and 
> cluster volume management need to be coordinated by the same system, and 
> above the filesystem layer, applications also need to be hooked into it.  
> This work is, in a word, incomplete.

The Cluster Volume Management of LVM2 for example _does_ use simple
cluster-wide locks, and some OCFS2 scripts, I seem to recall, do too.

(EVMS2 in cluster-mode uses a verrry simple locking scheme which is
basically operated by the failover software and thus uses a different
model.)


Sincerely,
    Lars Marowsky-Brée <lmb at suse.de>

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High Availability & Clustering
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