Server been very busy in last week / will analyse in morning.
Traffic on the server has been 50% up over the last 3 days compared to the January and February average; actually surprised how well it's coping. Educated guess the issue last night was during a deep database backup as at such times we lock the database to ensure that all the records no matter which table they're backed up from remain in step with each other in case we have to restore the system. Can't be more that a guess at this time ... if I had:
a) Note of error message / how it showed up
b) Note of time problem occurred
c) Duration (how long it lasted before it was [self]fixed)
I could either give you an easy or more certain answer or (if the issue was of a different sort) have the extra evidence I need to be able to know where to look.