MD3200 disk group and vdisk understanding

Question

Hi

we will buy a new powervault MD3200 and 2 Dell R620 for a small site. The R620 will be
running Citrix Xen Server.

You can find Powerpoint with hardware setup on http://www.mediafire.com/?5xcnkxuxlmo8vk9

Dell
PowerVault MD3200:

6*450
15k SAS disk
4*1TB
7.2k Nearline SAS (for backup purpose or applications/data that need less
performance)

Following
machines will be running virtual (more machines will follow in the future):

W2K8R2 RODC / FILE / PRINT / WSUS
W2K8R2 SQL 2008R2
Firewall
Win 7 with Mail Server
Win 7 dedicated app

I am thinking of configuring RAID 5 and RAID 5. Does this seem logical to you?

5*450Gb 15k + 1 hot spare
3*1Tb 7.2k + 1 hot spare

As this is our first experience with central storage I have a lot of questions regarding the disk group setup and virtual disks. I checked out some videos on techcenter / youtube and read some best practices and installation manuals of MD3200 and Citrix Xen Server.

As we do not have a lot of disks it seems logical to me to setup 2 disk groups. 1
for the fast 15k disks and 1 for the slower 7.2k disks. Seems ok to you?
Do I need to create a vDisk for every guest OS (check http://www.mediafire.com/?5xcnkxuxlmo8vk9)?
Creating a vDisk for dB data part / dB logfile part / fileserver files part seems logical to me.
Correct?
What about the smaller dedicated Workstations that are running virtualized; for
example order system.

C: OS
D:DATA

Do I need to create 2 virtual disks as well or better to create 1 vDisk and partition the disk in the Virtual machine itself
as there is no critical reason to create a separate vdisk for this data part. Only for logical understanding. OS (=Win7) on C-partition and work DATA on D-partition.

5. How will all these virtual disks influence the performance for this disk group? Does
the amount of vDisks have an influence on the performance?

1. 6. Can I increase vDisk space later or will this influence performance as well. Better

to use thin provisioning (if this is working for Citrix Xen Server 6.0)

Thanks for your input

Rgds

Bert

DELL-Jonathan S · Answer

Hi Bert,

From a support and compatibility perspective, the setup you have outlined is one possibility. It does make sense to separate the fast and slow disks in separate groups though you may find backing all of the applications you are trying to support on a RAID-5 to be slower than you expect. It is not uncommon and often recommended to put Exchange and SQL on their own RAID-10 for speed and redundancy. XenServer's support for LVM would likely afford you a lot of flexibility in terms of growing managing filesystem sizes within the limits of what guest operating systems allow. The best thing would probably be to fill out marketing.dell.com/.../desktop-virtualization-wp and have one of our virtualization solutions experts contact you to assist in designing the best solution for the hardware you're planning to buy. Since I myself am not such an architect I think they would be a better resource for you. Of course if you have support questions afterward, one of the forum techs such as myself can help!

PowerVault

MD3200 disk group and vdisk understanding

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