[linux-lvm] Shared VG, Separate LVs

Fri Nov 3 06:38:41 UTC 2017

Hi Eric, All,

Thanks for the input. I have got it working.

Here is what I did -
-------------------------------------------------------------------------------------------------------------------------------------------------------
Cluster Setup:
2 Nodes with CentOS 7.x: clstr01-nd01, clstr01-nd02
Common storage array between both nodes (8 shared volumes, presented as
/dev/mapper/mpatha to /dev/mapper/mpathh)
2 Port NICs, bonded (bond0) in each node

Resource group grp_xxx (nd01 preferred) -
Mount Point: /clstr01-xxx
Cluster IP: 172.16.0.101/24

Resource group grp_yyy (nd02 preferred) -
Mount Point: /clstr01-yyy
Cluster IP: 172.16.0.102/24

On both nodes:
--------------
Edit /etc/lvm/lvm.conf, and configure 'filter' and 'global_filter'
parameters to scan only the required (local and shared) devices.

Then run -
# /sbin/lvmconf --enable-cluster
Rebuild initramfs -
# mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img-orig
# dracut -H -f /boot/initramfs-$(uname -r).img $(uname -r)

Reboot both nodes.
--------------

After rebooting both nodes, run the following commands on any one node:
--------------
# pcs cluster start --all
# pcs resource create dlm ocf:pacemaker:controld op monitor interval=30s
on-fail=fence clone interleave=true ordered=true
# pcs resource create clvmd ocf:heartbeat:clvm op monitor interval=30s
on-fail=fence clone interleave=true ordered=true
# pcs constraint order start dlm-clone then clvmd-clone
# pcs constraint colocation add clvmd-clone with dlm-clone

# pvcreate /dev/mapper/mpath{a,b,c,d,e,f,g,h}
# vgcreate -Ay -cy clstr_vg01 /dev/mapper/mpath{a,b,c,d,e,f,g,h}
# lvcreate -L 100T -n lv01 clstr_vg01
# mkfs.xfs /dev/clstr_vg01/lv01
# lvcreate -L 100T -n lv02 clstr_vg01
# mkfs.xfs /dev/clstr_vg01/lv02

# pcs resource create xxx_mount ocf:heartbeat:Filesystem
device=/dev/clstr_vg01/lv01 directory=/clstr01-xxx fstype=xfs --group
xxx_grp --disabled

# pcs resource create xxx_ip_01 ocf:heartbeat:IPaddr2 ip=172.16.0.101
cidr_netmask=24 nic=bond0:0 op monitor interval=30s --group xxx_grp
--disabled

# pcs constraint location xxx_grp prefers clstr01-nd01=50
# pcs constraint order start clvmd-clone then xxx_grp

# pcs resource enable xxx_mount
# pcs resource enable xxx_ip_01

# pcs resource create yyy_mount ocf:heartbeat:Filesystem
device=/dev/clstr_vg01/lv02 directory=/clstr01-yyy fstype=xfs --group
yyy_grp --disabled

# pcs resource create yyy_ip_01 ocf:heartbeat:IPaddr2 ip=172.16.0.102
cidr_netmask=24 nic=bond0:1 op monitor interval=30s --group yyy_grp
--disabled

# pcs constraint location yyy_grp prefers clstr01-nd02=50
# pcs constraint order start clvmd-clone then yyy_grp

# pcs resource enable yyy_mount
# pcs resource enable yyy_ip_01
--------------

# pcs resource show
--------------
-------------------------------------------------------------------------------------------------------------------------------------------------------

Regards,

Indivar Nair

On Mon, Oct 16, 2017 at 8:36 AM, Eric Ren <zren at suse.com> wrote:

> Hi,
> On 10/13/2017 06:40 PM, Indivar Nair wrote:
>
> 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.
>
>
> OK! It sounds reasonable.
>
>
> 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?
>
>
> As said in the last mail, the new resource agent [4] will probably work
> for you, but I didn't test this case yet. It's easy to have a try - the RA
> is just shell
> script, you can just copy LVM-activate to /usr/lib/ocf/resource.d/heartbeat/
> (assume you've installed resource-agents package), and then configure
> "clvm + LVM-activate" for pacemaker [5]. Please report back if it doesn't
> work for you.
>
> The LVM-activate RA is WIP. We are thinking if we should merge it into the
> old LVM RA. So it may changes at any time.
>
> [5] https://www.suse.com/documentation/sle-ha-12/book_
> sleha/data/sec_ha_clvm_config.html
>
>
>
>
>> [1] https://github.com/ClusterLabs/resource-agents/blob/master/h
>> eartbeat/clvm
>> [2] https://github.com/ClusterLabs/resource-agents/blob/master/h
>> eartbeat/LVM
>> [3] https://www.redhat.com/archives/linux-lvm/2017-January/msg00025.html
>> [4] https://github.com/ClusterLabs/resource-agents/pull/1040\
>>
>
> Eric
>
>
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