Re: [linux-lvm] the lvm shared storage question of the week

[Jean Spirat <jeanspirat@squirk.org>]

Jonathan Brassow a �crit :
> Our testing group has machines that use AOE.  It works well with 
> CLVM.  However, they use their machines as a cluster.  It seems to me 
> that you want to carve up your storage, but you only want one machine 
> to use each piece.
>
yes each server will mount a part of the filesystem and not the same 
part on each. This mean a single lvm logical volume will be mounted only 
on one host.

> LVM manual briefly mentions CLVM (should apply equally well to debian):
> http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/Cluster_Logical_Volume_Manager/index.html 
>
yes it just speak about it but there is no doc at all, nothing tells us 
if it listen on a tcp port or just communicate by using data on the disk 
or anything about the setup. Also it speak about special configuration 
in lvm.conf but nowhere i see WHAT should be configured :)

i guess with:

locking_type What type of locking to use. 1 is the default, which use 
flocks on files in locking_dir (see below) to avoid conflicting LVM2 
commands running concurrently on a single machine. 0 disables locking 
and risks corrupting your metadata. If set to 2, the tools will load the 
external locking_library (see below). If the tools were configured 
--with-cluster=internal (the default) then 3 means to use built-in 
cluster-wide locking. All changes to logical volumes and their states 
are communicated using locks.

that it should use

locking_type=2


but is this enough ?
>
> You will want to come up to speed on the cluster infrastructure (at 
> least the setup) if you want to use CLVM....
>
sorry i am not native english speaker, what do you mean by that ?

regards,
Jean.