On Saturday 07 August 2010, Andrew R Paterson wrote:
> On Saturday 07 August 2010, Keith Edmunds wrote:
> > On Sat, 7 Aug 2010 21:14:14 +0100, andy.pater...@ntlworld.com said:
> > > I have been running for years without backups - using the relatively
> > > simple notion that raid mirroring is arguably as good as backups
> >
> > NO!
> >
> > It might work for you, which is fine; however, there is a world of
> > difference between RAID and backups.
> >
> > RAID will hopefully protect your data in the event of a hardware failure,
> > there is a small subset of classes of hardware failure that it will not
> > protect against.
> >
> > Backups will allow you to restore lost data. The data may be lost by:
> > - a hardware problem
> > - finger trouble ("rm -rf *" in the wrong directory, or "cp
> >
> > backupversion currentversion")
> >
> > - subsequent editing ("I want this file as it was before the changes I
> >
> > made last Thursday")
> >
> > - a software bug
> > - a break-in
> > - power failure at the wrong time
> > - theft of your PC
> > - deleting, only later realising that you still need the data
> >
> > ...and so on. RAID protects you against some of the first category, and
> > none of the rest.
> >
> > As I say, if it works for you, fine, but it is wrong to assert in general
> > that "raid mirroring is arguably as good as backups": it isn't.
> >
> > FWIW: I've resorted to backups to recover from each of the first four
> > above, and the last. All my systems run RAID.
> >
> > Keith
> >
> > --
> > Next meeting: Blandford Forum, Tuesday 2010-09-07 20:00
> > http://dorset.lug.org.uk/ http://www.linkedin.com/groups?gid=2645413
> >
> > Chat: http://www.mibbit.com/?server=irc.blitzed.org&channel=%23dorset
> >
> > List info: https://mailman.lug.org.uk/mailman/listinfo/dorset
>
> I did say "arguably".
> As I said attach a new temporary (usb?) device, resync detach == backup -
> no downtime.
And I am -obviously- talikng about mirroring (raid 1).
--
Andy Paterson
--
Next meeting: Blandford Forum, Tuesday 2010-09-07 20:00
http://dorset.lug.org.uk/ http://www.linkedin.com/groups?gid=2645413
Chat: http://www.mibbit.com/?server=irc.blitzed.org&channel=%23dorset
List info: https://mailman.lug.org.uk/mailman/listinfo/dorset
