Re: Re: Compressing DVD ISO Images

["christopher purves" <CHRIS_PURVES@xxxxxxx>]

I would have to agree .....

I lost a Raid 5 system which was UPSed with 2 disks failing. Grr.

I now have 3 copies of the family jewels (photos etc) and DVD backups too.
I
still have a raid 5 terrasation and all other pcs are raid1 but I don't
have
too much faith.

The problem with large media arrays is that with say 16 disks you are
almost
guarenteed a failure in 1 year (unless you buy the expensive scsi drives
which have better mtbf). And there is a real chance that 2 might fail -
especially as they are probably all the same make, made at the same time on
the same production line etc etc etc).


Chris


>From: "Phil Harris" <phil@xxxxxxx>
>Reply-To: ukha_d@xxxxxxx
>To: ukha_d@xxxxxxx
>Subject: Re: [ukha_d] Re: Compressing DVD ISO Images
>Date: Tue, 14 Feb 2006 09:53:52 -0000 (GMT)
>
> > Yeah, I have since looked it up, and it does do raid5, but since
they
> > only take 4 disks, that means 25% of the capacity is lost to the
parity
> > info.
> >
> > I think Id still opt for an 8 drive raid5 array, which will mean
only
> > 12.5% wastage.  With the Gb per £ ratio currently peaking at
the 250Gb
> > drive mark, that should make a 8x250Gb (1.75Tb available) setup
possible
> > for around £850 (PC + drives) - compared to the 1.6Tb
Terrastation (only
> > 1.2Gb available in Raid 5) which costs around £150 more.
> >
> > Mal
>
>For media servers do you *REALLY* need RAID though?
>
>If you are using *HARDWARE* RAID using a PCI or mobo based RAID
solution
>then you really must buy either a second RAID card or mobo as a spare
in
>case either develop a fault as you may find that in a couple of years
time
>if your controller (rather than your drive) fails then you're
completely
>stuffed if the controller is no longer available to be replaced. If you
>have a power supply fail whilst your nice safe RAID5'd media server is
>writing to the array then you can easily get a couple of drives with
>corruptions which will cause you to lose data and if you have a drive
fail
>in a RAID 5 array whilst it's rebuilding (which isn't beyond the realms
of
>possibility since it's likely that all your drives will have been
bought
>at the same time and will be from the same batch) then you will loose
the
>whole damn lot.
>
>I played with several RAID solutions (both Hardware and Software) under
>Linux, Windows and MAC OSX and in the end decided that should a drive
go
>down on my media server then I could live with having to re-rip those
>movies again - a 300Gb drive full of movies is about a weekends work to
>re-rip and of course you have the originals to do that with don't you?
>
>It seems that there is a lot of belief that as long as you have some
form
>of "RAID 5" solution then you can sit back safe in the
knowledge that your
>data is secure and I know I'm going to get shot to sh*t on this for
>contradicting the crowd but I don't consider it quite that
cut-and-dried.
>
>The only data that I have flagged up as "too important to
lose" is the
>family documents directories, the family digital photos and my
extensive
>collection of "porn" (and for anyone that doesn't know me
that means TVR
>videos rather than what you might be thinking of) which is *WAY* less
than
>160Gb and so I simply mirror that drive using two *DISSIMILAR* drives -
>curently the primary drive is a 160Gb Maxtor (which is probably in the
>order of six years old) and a 160Gb Hitachi (which is now probably 18
>months old) - in separate enclosures (with separate PSUs) and one on
>firewire whilst the other is on USB to minimise the chances of them
both
>failing in the same way and at the same time.
>
>Phil
>
>
>
>
>Yahoo! Groups Links
>
>
>
>
>
>
>