Re: Battery Backed Cache for RAID

> On Wed, Sep 14, 2005 at 11:28:43AM -0700, Jeffrey W. Baker wrote:
> > On Wed, 2005-09-14 at 11:25 -0700, Peter Darley wrote:
> > >     I'm getting a new server for our database, and I have a quick
> question
> > > about RAID controllers with a battery backed cache.  I understand
that
> the
> > > cache will allow the cache to be written out if the power fails to
the
> box,
> > > which allows it to report a write as committed safely when it's
not
> actually
> > > committed.
> >
> > Actually the cache will just hold its contents while the power is
out.
> > When the power is restored, the RAID controller will complete the
writes
> > to disk.  If the battery does not last through the outage, the data
is
> > lost.
>
> Just curious: how long are the batteries supposed to last?

For the length of time it will take for you to get fired for not getting
the server running plus one hour :).

Merlin