>>An electrical energy cut?

> If you are running with Forced Writes off then a power cut
> can corrupt a database. Otherwise, a power cut can cause
> uncommitted data to be lost. However, a surge when power
> is restored can damage your hard disk.

It is worth noting that some hard-drives (or drive controllers)
have their own write cache (independent of the operating
system); flushing operating system write-buffers does _not_
guarantee that HDD write cache will also be flushed. See:
http://www.storagereview.com/guide/cacheWrite.html

--
Geoff Worboys
Telesis Computing