[ClusterLabs] LVMLockD Recipe for Fedora 37 PCS GFS2 Shared Storage Cluster

[Gregory Carter]

I recently had some time to read the documentation for LVM Shared Storage
using PCS and found that there wasn't any documentation on how to set it up
using lvmlockd/GFS2/Fencing in a shared configuration.  There are a couple
replication scenarios out there that use DRDB/Cloning which I might try if
this isn't possible.

Everything I have found is CLVMD based or is incredibly old created way
before LVMLockD deprecated CLVMD.  So I decided to take the guessing route:

So this is how far I got:

1) I created a LVM volume with GFS2 physically formatted volumes.
vgcreate "vmgfs2" /dev/sdb1 /dev/sdc1 /dev/sde1 /dev/sdg1 --shared
lvcreate -n "smvms" -L 50G "vmgfs2"

2) I formatted a GFS2 file system on the smvs segment:
mkfs.gfs2 -p lock_dlm -t vmgfs2:smvms -j 8 /dev/vmgfs2/smvms

3) I then fenced the block devices with stonith like so:

pcs stonith create scsi-shooter fence_scsi
pcmk_host_list="hyperv0001.cluster hyperv0002.cluster"
devices=/dev/disk/by-id/wwn-0x6001405f0efeeeb51af42c09971344de,/dev/disk/by-id/wwn-0x6001405fbe61a5c9e234a81968805ac3,/dev/disk/by-id/wwn-0x60014055c9a285a61214064a7ad60ccd,/dev/disk/by-id/wwn-0x600140565c8b9cb3f874d7f89ef4afa1
meta provides=unfencing

4) Now for the lvm.conf configuration, that part wasn't obvious.  Since I
do not have any lvm volumes on the hypervisors other than the block devices
assigned specifically for shared storage I didn't have any filters setup.
(i.e. the hypervisors main block devices are nvme and the other block
devices are not part of a shared volume.)

That being said I set the following up in lvm.conf:
use_lvmlockd = 1
system_id_source = "none"
volume_list = []

Some more info:

# vgs
 VG     #PV #LV #SN Attr   VSize     VFree
 vmgfs2   4   1   0 wz--ns <1023.91g <973.91g
and
# vgs
 Reading VG vmgfs2 without a lock.
 VG     #PV #LV #SN Attr   VSize     VFree
 vmgfs2   4   1   0 wz--ns <1023.91g <973.91g

I assume they both have to have a shared attribute set.

Both machines boot with lvmlockd enabled at boot time.

It also was suggested I setup my initrd on the hypervisors to load the
lvm.conf file at startup with the proper configuration options more
immediate.

So I then updated my initrd like so:
dracut -H -f /boot/initramfs-$(uname -r).img $(uname -r)

5) Next I defined a activation resource, which I took from some relatively
recent documentation I found out on the web:
pcs resource create vmgfs2_pcs ocf:heartbeat:LVM-activate vgname=vmgfs2
vg_access_mode=lvmlockd --group vmgfs2

This however leads to some issues:

Cluster name: vmgfs2
Cluster Summary:
 * Stack: corosync
 * Current DC: hyperv0001.aesgi.com (version 2.1.4-4.fc36-dc6eb4362e) -
partition with quorum
 * Last updated: Fri Dec 30 17:26:45 2022
 * Last change:  Fri Dec 30 14:48:38 2022 by root via cibadmin on
hyperv0001.aesgi.com
 * 2 nodes configured
 * 4 resource instances configured

Node List:
 * Online: [ hyperv0001.aesgi.com hyperv0002.aesgi.com ]

Full List of Resources:
 * Clone Set: dlm-clone [dlm]:
   * Started: [ hyperv0001.aesgi.com hyperv0002.aesgi.com ]
 * scsi-shooter        (stonith:fence_scsi):    Started hyperv0001.aesgi.com
 * Resource Group: vmgfs2:
   * vmgfs2_pcs        (ocf::heartbeat:LVM-activate):   Stopped

Failed Resource Actions:
 * vmgfs2_pcs_start_0 on hyperv0002.aesgi.com 'not configured' (6):
call=16, status='complete', exitreason='lvmlockd daemon is not running!',
last-rc-chan
ge='Fri Dec 30 14:53:17 2022', queued=0ms, exec=1429ms

Daemon Status:
 corosync: active/enabled
 pacemaker: active/enabled
 pcsd: active/enabled

I am not sure why I get a lvmlockd not running response as it is configured
to run at bootup.

But since I used a variety of locations to put together this information, I
was wondering if there wasn't a location that already has this specified?
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