We've been using OMSA with CentOS 7 for many months and then a few weeks ago, OMSA upgraded on the usual overnight yum run.

Not normally an issue. We usually see SNMP monitoring fail for a few minutes during that but everything comes back.

However, this didn't happen on a number of servers of varying chassis. It's worth noting that some worked fine but others didn't (similar hardware etc).

[root@xxxx ~]# omreport storage controller
No controllers found

Machine can see the card and is running just fine.

[root@xxxx ~]# cat /proc/scsi/mptsas/4
ioc0: LSISAS1068E B3, FwRev=00192f00h, Ports=1, MaxQ=266

Drives can't be seen via OMSA interface either.

At a loss what now to try and what changed in the upgrade to cause it to break entirely.