[sclug] Raiding partitions

[Keith Edmunds]

On Sat, 09 Apr 2005 13:47:24 +0100
Neil Haughton <n.a.haughton at bigfoot.com> wrote:

> Can this done with an IDE PCI RAID card (I've seen a cheap PCI IFDE RAID 
> card in Maplins), or is it best done using software RAID?

It can be done with a RAID card, but I wouldn't. The problem is that most
RAID cards store the data in a proprietary format on disk, so if/when your
RAID card breaks you are left with just your backups. Mirroring in the
Linux kernel is very efficient and just works. That's what we do with just
about every server we build. You can remove one disk of a Linux mirror
pair, put it in another system and boot it - no proprietary formats in
sight.
 
> BTW I'm using Mandrake 10.0 and WinXP Pro (dual boot), so my 40G 'home' 
> partitions are each really two partitions, a 20G Linux /home and a 20G 
> Windows 'drive D:'. I was hoping to get both pairs of partitions to be 
> synchronised when I run Linux (which is most of the time).
>
> Is this the right approach, and how should I proceed? Any pitfalls to 
> look out for?

This won't work with Windows. There's a software RAID howto which should be
Google-able. If you're only wanting to mirror data (as opposed to boot from
a RAID set) then it's pretty straightforward to do. Booting from RAID isn't
that hard, but it is a little more tricky.

> BTW If you get the temptation to buy an IBM/Hitachi DeskStar drive, 
> don't. I've twice in succession had mine fail under warranty within 2 
> years. Must be the most unreliable drives I've ever come across.

We've had very poor experiences with IBM disks. That said, for any
manufacturer you'll find someone who has had a bad experience. FWIW we use
Maxtor disks now, which has worked out pretty well (so far!).

Keith

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