Re: Re: Compressing DVD ISO Images

["Phil Harris" <phil@xxxxxxxxxxx>]

> 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