Present 2 logical disks to Win 2008 or Present 1 and partition it?

[Jake M_1]

Hi,
I have picked this forum because this question came to light whilst installing a new HP DL380 G6, hopefully there is someone in here with an answer :)

Server Config
HP DL380 G6
2 x 72GB 10k SAS (2.5") - In a Raid 1 (mirror config)
Plenty of processor and RAM!!
This server is to be the first of my new 2008 DC's

I am wondering which, if any, of the following 2 configurations would be the most appropriate.

Configuration Option #1
------------------------
Using HP Array Configuration Utility present a single logical disk, with maximum space, to my server and partition it.

Partition 1 (C Drive) = 52GB (Microsoft Minimum for 2008 Boot Partition)

Partition 2 = the rest of the space (18GB)

Install windows on partition #1 and the page file with a pre defined size on partition #2.


Configuration Option #2
-----------------------

Present 2 separate Logical disks and
DO NOT PARTITION

Logical Disk #1 = 52GB (Microsoft Minimum for 2008 Boot Partition)

Logical Disk #2 = the rest of the space (18GB)



I am curious whether there is a benefit to either presenting 2 separate logical disks or just a single logical disk and partitioning it....

Any thoughts much appreciated,
Thanks

[Michal Kapalka (mikap)]

hi,

the "Configuration Option #1" is usually used.

mikap

[Jake M_1]

Hi,
Thanks for the reply.
I know historically this is the usual method. But I believe thats because unless you are using fancy equipment to allow you to present logical drives outside of windows (I.e. my RAID controller in my case) You only had one option and thats to partition the disk.

The RAID controller gives me the ability to present 2 separate logical disks to windows, and make windows 'think' that they are actually separate disks.

I was wondering if there were any advantages / disadvantages to doing it either way.

For example, one advantage of presenting separate logical disks is that you can expand any of your logical disks whenever you like using the standard windows tools rather than having to 'rearrange' disk space using 3rd party tools etc....

But are there any performance increases or impacts that are known etc...?

Thanks,

[Diego Castelli]

it's important to be aware of disk performances in a windows environment.

if you don't care too much about, you can choose whatever.

Windows is managing disk queues per physical disk, so there is a queue of operations per LUN (as windows looks at luns like phys. disks)

If performances could became an issue, you should certainly look at solution 2, since the windows queue is almost certainly not filling up all the controller's capability.

in a solution where, for example, you are going to install a DB it is recommended that you split space in LUNS: it'll give you better performances for sure!

Hope this helps.

(sorry for mistakes: today my english is sleeping with the part of me that lays at home, in my bed.)

[Jake M_1]

Hi,
Very helpful, thanks for taking time to answer my question :)
Jake

[wobbe]

Diego, are you saying that if I would create 3 logical units with the array controller on one disk and use this for example exchange or an ms sql installation it would be quicker then if I would create 3 partitions using windows?

52GB the minimum for windows boot patition!!! Iâ M SCHOCKED!

[Diego Castelli]

wobbe, if you use a single disk you'll be slow anyway. :-)

you will be probably quicker than using a single LUN and partitioning, yes.

I'm not talking to the wind, i'm sure of what i'm saying.