RAID Config

1 Sep 2006 7:15 PM

skhips

Hi and thanks or reading.

Ref Hardware RAID on Dell Poweredge 1950.

Normally on our servers we build 2 disks on a RAID 1 for the O/S and three
disks on a RAID 5 for the data / apps and have a hot spare assigned.

1. We are getting a large amount of Dell 1950 servers with 4 HDD and a RAID
contoller so it looks like we will lose out hot spare capability which I
dont really want to do.

2. What is the best type of RAID for the o/s (read it didnt like RAID 5 but
is this when its only software RAID.

3. What would be the best RAID config to have a O/S partition and a data or
app or exchange 2000 partition.

thanks

1 Sep 2006 8:40 PM

wdewey

This is just my opinion, but RAID 5 with a hot spare (if you can afford to
lose that much disk space) would be the best option. RAID 5 you get aprox
2/3's of your storage space plus striping. RAID 1 you only get 50% of your
storage space and I believe that you need an even number of drives.

Bill

2 Sep 2006 10:22 PM

Robert Moir

skhips wrote:

> Normally on our servers we build 2 disks on a RAID 1 for the O/S and
> three disks on a RAID 5 for the data / apps and have a hot spare
> assigned.
>
> 1. We are getting a large amount of Dell 1950 servers with 4 HDD and
> a RAID contoller so it looks like we will lose out hot spare
> capability which I dont really want to do.
>
> 2. What is the best type of RAID for the o/s (read it didnt like
> RAID 5 but is this when its only software RAID.

"best type" is a matter of opinion and need I guess. A Mirror ought to be
sufficient for most cases.

> 3. What would be the best RAID config to have a O/S partition and a
> data or app or exchange 2000 partition.

What are we using the Exchange Server for? Front End / Back End config
(and if so which one?). Mailbox store? Public Store? Mail Bridgehead?
Every damn thing on one box?

As a bare minimum, I would always want Exchange database to be seperate
from the OS, and ideally from it's logfiles too. So my ideal Exchange
install might look like this (assuming that we're talking about a general
exchange server rather than a specialised server)

RAID 1 > Partition 1 > Operating System
RAID 1 > Partition 1 > Exchange Logfiles | Partition 2 > SMTP service
'scratch' volume
RAID 5 > Partition 1 > Exchange Databases

If I was asked to use a 4 disk system for a _busy_ exchange server, my
first thought would be to reject it as inadequate. If It was for a
relatively quiet system, or other considerations forced me to compromise,
I'd probably lay it out as follows

RAID 1 > Partition 1 > Operating System | Partition 2 > Exchange
Logfiles
RAID 1 > Partition 1 > Exchange Databases | Partition 2 > SMTP service
'scratch' volume

--
--
Rob Moir, Microsoft MVP for Security
Blog Site - http://www.robertmoir.com
Virtual PC 2004 FAQ -
http://www.robertmoir.co.uk/win/VirtualPC2004FAQ.html
I'm always surprised at "professionals" who STILL have to be asked:
"Have you checked (event viewer / syslog)".

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