Ocfs2

Check IPs of SAN volumes

iscsiadm --mode session

/san failing to stay unmounted on Cent7?

Comment its line out of /etc/fstab.

systemctl stop san.mount
systemctl daemon-reload

Check again after a few seconds on all nodes:

partprobe
mount | grep san

If it's not mounted, do your disk work, then uncomment the /etc/fstab line

systemctl daemon-reload
systemctl restart ocfs2

Should be mounted again at the proper size.