1404 server mounted the wrong drive

Hi all,

Our Ubuntu server has a ssd boot drive /dev/sda and mounts a 4tb drive
for owncloud. Funny thing is there is 2 4tb drives in the box /dev/sdb/
& /dev/sdc . Normally it loads the correct drive which is specified in
/etc/fstab by its uuid. This should be /dev/sdc. Yesterday after the
updates it mounted /dev/sdb. How could it suddenly mount the other hard
drive? It sort of cause panic due to files suddenly being old etc etc

Linux: 4.4.0-96-generic x86_64
Description: Ubuntu 14.04.5 LTS
Codename: trusty

yesterdays dmesg here <a href="" title=""></a>