[linux-lvm] cluster - lvm

[Michael Clark]

I'm using LVM in a cluster.

There are a few caveats. It does not support distributed updates
and locking on metadata so you must be extra careful when making
changes to logical volumes.

If you need to make any changes to logical volumes, you must do
it with only one host online. I have successfully done LVM metadata
updates in a cluster without rebooting nodes by unmounting all LVM
partitions on all nodes but one and also removing the SCSI module
(just to make sure nothing is cached). After performing the
LVM modifications on the remaining node, I then re-probe the SCSI
module on the other nodes and rerun vgscan. All seems okay and
the new volumes are detected.

What appears to be needed for better cluster support is at least some
simple locking on the metadata to enforce the single node exclusive
access to cluster metadata when performing changes, because at the
moment there are no checks on operations which could potentially
corrupt data.

~mc


On Tuesday, March 26, 2002, at 03:37 PM, shlim wrote:

> Hello.
>  
> Does the current LVM version support cluster system??
>  
> If LVM does not support cluster system. what is required to support 
> that??
>  
>  
>  
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