Setup GFS2 shared storage in Proxmox VE 6 on top of iSCSI LUN

howto-gfs2-proxmox6.txt

#-- there're four proxmox boxes (vm-box-1..vm-box-4)
#-- all commands should be issued on one of the boxes

for i in $(seq 1 4); do ssh vm-box-$i apt install dlm-controld gfs2-utils -y; done
for i in $(seq 1 4); do ssh vm-box-$i 'echo DLM_CONTROLD_OPTS="--enable_fencing 0" >> /etc/default/dlm; systemctl restart dlm'; done
#-- check if /dev/misc folder exists. if not, run:
for i in $(seq 1 4); do ssh vm-box-$i "systemctl stop dlm; rmmod gfs2; rmmod dlm; sleep 3; systemctl restart udev; sleep 3; systemctl start dlm"; done

#-- add iscsi storage to proxmox (check shared)

#-- -j number should match the number of proxmox boxes, replace sdf with your iscsi device name
mkfs.gfs2 -t MyClusterNmae:sdf-iscsi-lun0-gfs2 -j 4 -J 64 /dev/sdf

mnt="/mnt/pve/iscsi-lun0-gfs2"
uuid=$(blkid /dev/sdf | sed -n 's/.*UUID=\"\([^\"]*\)\".*/\1/p')
escaped_mnt=$(systemd-escape -p --suffix=mount $mnt)
cat > "/etc/systemd/system/$escaped_mnt" <<EOT
[Unit]
Description = Mount GFS2 share over iSCSI LUN
Wants=open-iscsi.service dlm.service
After=open-iscsi.service dlm.service

[Mount]
What=/dev/disk/by-uuid/$uuid
Where=$mnt
Type=gfs2
Options=_netdev,acl

[Install]
WantedBy=multi-user.target
EOT

for i in $(seq 1 4); do scp "/etc/systemd/system/$escaped_mnt" vm-box-$i:/etc/systemd/system/; ssh vm-box-$i "mkdir -p $mnt; systemctl daemon-reload; systemctl enable \"/etc/systemd/system/$escaped_mnt\""; done

#-- add directory storage proxmox (check shared) for /mnt/pve/iscsi-lun0-gfs2

#--------------------------------------------------------

#-- to revert everything back:
#-- disable/remove directory storage
for i in $(seq 1 4); do ssh vm-box-$i "systemctl stop \"$escaped_mnt\"; systemctl disable \"$escaped_mnt\"; systemctl daemon-reload"; done
#-- disable/remove iscsi storage in proxmox
#-- if no other iscsi targets exist, delete all sessions:
for i in $(seq 1 4); do ssh vm-box-$i "iscsiadm -m node --logout; iscsiadm -m node --op delete"; done
#-- otherwise use -T switch to specify certain target in the above commands