Hello,
I see you reported a similar issue here back last August:
Is this the same error, or a different system and/or error ? If it's a different one, how did you resolve the issue above last year ? And would the same solution be applicable again now ?
In any case, one question I'd ask is if there are any other messages being logged either side of this one ? It's not too likely that this is happening in isolation. Normally if errors are happening that are severe enough to stop a system from booting, you'll at least get messages indicating things like a filesystem could not be mounted, or that other hardware and/or software errors occurred. Do you see anything else being logged ?
And then lastly I'd ask the time-old question: has anything changed between when this system last successfully booted, and now ? Have any disks been replaced, re-seated or removed ? Has the CPU or memory or any other aspect of the server's hardware changed ? Were OS updates or upgrades attempted ? Any change at all, no matter how insignificant or irrelevant it might at first appear, could be useful to know about.