Lefthand with Citrix Xen Server

[Shevary]

Hi
I am new to Lefthand, we are running Citrix Xen Server 5.5 on HP Blade C3000and with Lefthand P4300, we have about 10 VMs running on Xen Serve, and I am cutting individual luns on the Lefthand and present it to the VMs on the Xen Server.

We have second HP Blade C3000 with attached storage and we are using this storage to install the VMs .

So I would like to know your ideas and as always it's good to hear from others especially from those who are using them day-by-day.

I want to use the Lefthand for both blades and Xen server, what is the best way to manage the VMs on Lefthand?

Do you cut individual Luns for each VM? or do you create one Luns for the all VMs on each blade?

I want utilize the LeftHand with Xen Server, I am thinking to use a Lefthand and create big lun and present that lun to both Xen Server, and use it as pool, because I want do Xen motion between the blades.

Regards,
Hevary

[JLF175_1]

We have a P4000 unit which manages the ~40 VMs we have across three hosts. Our Citrix XenApp farm is six servers.

I really don't think how you split up the datastores for the VMs will matter. I currently have some Citrix server VM files intermixed with other VM server files on the same datastore with no noticeable impact on performance.

In my experience with Citrix it is much more important to monitor RAM and CPU utilization rather than hard drive performance.

[Brent Nussbaum]

Hi Hevary,
We have been running the lefthands with Xenserver for a little more than a year now. The strategy we took was we created a Storage repository for each VM. We then used microsoft Iscsi to attach any additional drives. This way we can utilize the san snapshot technology to take snapshots of the data, and be able to restore them with any windows server. If you present all your drives through xenserver, it is my understanding that the only way to access that data would be to attach it back to a xenserver. The only problem with creating a storage repository for each vm is you kind of get a lot of them. We only run about 15 VM's so it isn't that big of a deal to us.
As long as both your blades can see the storage, it should allow you to do xenmotion and HA.

[Dave Finch]

Hevary,

We have about 20 VMs deployed on 5 XenServers. We also have one storage repository/lun per VM. The advantage is that we can manage snapshots for each VM. Data drives are connected over MS iSCSI. Another advantage of this approach is better utilization of the SAN. Lots of file create/delete activity increases the amount of SAN space used by a thin provisioned volume. By putting transaction log volumes on thier own lun/volume, it concerves SAN space.

The disadvantage is that you have many volumes/Storage Repositories to manage. Also, if you are in a disaster recovery scenario (or just testing), there's a risk that the MS iSCSI connections could connect back to the production data volume. So, you need to either modify the VMs network settings or use some other network scheme to prevent access from the DR site to the production site.