Re: [linux-lvm] Shared VG, Separate LVs

[Indivar Nair <indivar.nair@techterra.in>]

[-- Attachment #1: Type: text/plain, Size: 1957 bytes --]

Thanks Eric,

I want to keep a single VG so that I can get the bandwidth (LVM Striping)
of all the disks (PVs)
  PLUS
the flexibility to adjust the space allocation between both LVs. Each LV
will be used by  different departments. With 1 LV on different hosts, I can
distribute the Network Bandwidth too.
I would also like to take snapshots of each LV before backing up.

I have been reading more about CLVM+Pacemaker options.
I can see that it is possible to have the same VG activated on multiple
hosts for a GFSv2 filesystem.
In which case, it is the same PVs, VG and LV getting activated on all hosts.

In my case, we will have the same PVs and VG activated on both hosts, but
LV1 on Host01 and LV2 on Host02. I paln to use ext4 or XFS filesystems.

Is there some possibility that it would work?

Regards,


Indivar Nair



On Fri, Oct 13, 2017 at 2:41 PM, Eric Ren <zren@suse.com> wrote:

> Hi,
>
> With CLVM / HA-LVM on a 2 node cluster -
>>
>> Is it possible to have a shared VG but separate LVs, with each LV
>> exclusively activated on different nodes in a 2 node cluster.
>> In case of a failure, the LV of the failed node will be activated on the
>> other node.
>>
>
> I think clvm can do what you want if you perform LVM commands by hand.
> But, with HA cluster manager (pacemaker) you cannot
> do it with the current resource agents (clvm + LVM) [1] [2], because they
> do failover at a VG basis.
>
> We are currently working on new resource agents [3] for lvmlockd [4]. The
> new agents can do activation on LV basis, but I won't
> recommend doing that if there's no strong reason. It makes things much
> more complicated.
>
> [1] https://github.com/ClusterLabs/resource-agents/blob/master/
> heartbeat/clvm
> [2] https://github.com/ClusterLabs/resource-agents/blob/master/
> heartbeat/LVM
> [3] https://www.redhat.com/archives/linux-lvm/2017-January/msg00025.html
> [4] https://github.com/ClusterLabs/resource-agents/pull/1040
>
> Eric
>
>
>

[-- Attachment #2: Type: text/html, Size: 3239 bytes --]