Re: [PCTECH] Linux RAID

[Ken Sims <mdrg5003@xxxxxxxxx>]

Hi David -

> Ken Sims wrote:
> > Yep ... I've made major hardware changes on my Linux firewall and my 
> > Linux server and never had to do anything special except when I went from 
> > non-RAID to a bootable software RAID-1 (mirrored drives) configuration.
>
> What are you using for RAID?

I'm not sure whether you're talking hardware or software, so I'll give you 
both sides.

Both systems are identical except for the specific model of processor and 
the amount of RAM and some of the software installed.  (The server has a 
faster processor, more RAM, and some software that doesn't need to be on 
the firewall system.  [Neither has any gooey interface software installed.])

Hardware-wise, even though the motherboards support hardware SATA RAID, I'm 
using the software RAID with a pair of 80GB IDE Western Digital hard drives 
in each system.  Each hard drive has three partitions: the root partition, 
a swap partition (so far never needed because I have plenty of RAM), and a 
partition where I put my own stuff: scripts, websites and Apache config 
file, email and postfix config files, etc.

Each of partitions is mapped to its counterpart on the other drive so that 
it looks to the application software the same way it would look if it were 
a non-mirrored system with just the primary master IDE drive.

The distribution I'm running is RedHat 9 (yes, I know it's no longer 
supported, but it's running fine so I have no immediate plans to upgrade 
and haven't even decided if I want to move to Fedora or go to some other 
distribution entirely).

One of the things I like about the software RAID is that you can apply RAID 
to RAIDed volumes.  If these systems were highly critical, I could do 
something like setting up four RAID-1 pairs, then make those four volumes 
as a RAID-5 set.  Or make two RAID-5 sets and then mirror them.  Plus the 
fact that the drive geometries don't have to be the same.  Mine are, but 
they don't have to be.

--
Ken
http://www.ke9nr.net/
Opinions expressed are my own and do not necessarily represent the views of 
my employer or anyone in their right mind.