[plug] Config new h/w for RAID XP and Linux

[Craig Ringer]

On Fri, 2005-04-29 at 07:59 +0800, Paul Loring wrote:
> That isn't quite right.
> 
> With two 160GB hard drives you can have a mixture of RAID 0 and RAID 1, eg, 
> 60GB of drive a and drive b could be RAID 0, ie, 120GB in all stripped across 
> two drives for performance, and 100GB on each drive mirrored for redundancy. 

This is much the same as can be done with Linux's software RAID (your
Intel RAID is, after all, software RAID done in the driver, plus some
BIOS hooks).

> The more advanced RAID types like RAID 5 and 10 require 4 drives.

Three for RAID 5, but it seems to perform much better on 4.

> This Intel approach may be specific to this hardware, and my concern is that it 
> may not be accessible to Linix.

It *may* be with Intel drivers (if they provide any), or maybe with the
dmraid drivers. I'm not sure - that configuration is pretty weird. Doing
a test install to see wouldn't hurt.

> I'm not sure of the RAID or Linux terminology, but using DOS, I could assume 
> that O/S would go in their own primary partition in RAID 1, hence I would need 
> one for XP another for Linux.

That's right, though Linux typically uses more than one partition - at
least a swap partition and root partition, plus often /home &/or /boot;
sometimes folks separate out /var, /opt, /usr and /usr/local too. If you
find all that confusing, just stick to root and swap for now.

> In the past I have had a partition for 
> applications and another for data, so backing up to CD was just a copy of the 
> data partition. The RAID 0 would need a work file or scratch space partition, 
> would this be sharable between Linux and XP?

Probably not. Both can read fat32, but both have various limitations on
that filesystem. They can't share swap or, AFAIK, any other common
read/write filesystem types.

> I don't know the limitations of sharing files between Linux and XP.

Largely limited to fat32 only, though Linux has good read-only NTFS
access.

> Hence I don't know if I would need 
> duplicate partitions for each O/S, eg, a Linux and a separate XP Games 
> partition, etc?

Yes.

Personally, I gave up on making lots of partitions under win32 ages ago
(except on servers). Windows insists on putting lots of key data in
\Documents and Settings\ anyway, and if the OS partition is nuked you
have to reinstall all your apps because of the registry, so I just don't
see the point.

I don't see that RAID makes much difference either, really. My view on
RAID 0 is "use it only if you place no value on what is stored in it."
I'm much happier just sticking to RAID 1/5/10 .

-- 
Craig Ringer