Has anyone played around with Xen Desktop and Adobe Permier / Photoshop? Is this sort of thing possible with "normal" server hardware (ie, dual proc or less & small number of drives - let's say 5ish drives or less)?
You're probably not going to get a good experience out of crappy hardware like that. Run a trial on it and see how it does.
Are you planning on using ICA-HDX? I've used VMware View PCoIP and it's just like sitting down at a desktop- Snappy menus, full video, USB support, etc etc. I've heard that ICA-HDX is a similar experience.
VDI is very I/O intesive.
You need a SAN for storage to provide a good user experience.
I poked around with XenDesktop5 on an ESXi box, running on a Dell PE2850 (2 dual core CPUs, ~7.5GB RAM). Experience was horrible. Drives never stopped churning. Although they were in a RAID5.
And that was only running a single virtual desktop and no apps.
Quoted for truth, we are doing a VDI trial using Microsoft's VDI and windows 7. 10 users have crippled a box that ran a 3,000 user hosted exchange 2010 environment with ease (2x Xeon E5560s, 48GB RAM, 146GBx4 15K SAS6 RAID 5, ATI HD5570). Now the users think it is great, they claim the performance is better then their current XP desktops but our poor server would like a break.
So anyone who is considering VDI, get a fiber or SAS HBA SAN with fast disks, A LOT of RAM (Assume 4GB per user) and some nice processors.
You don't need 4GB per client. Usually far less than that on VMware vSphere. Spindle count is key and it's where we see people grossly underestimate requirements. A very well tuned VDI VM is like 8 IOPS. A normal desktop without any thought is usually in the range of 30 IOPS. So you can't just convert your normal deployment over to a VM and expect good things..you also need to look at what tools, AV, inventory, etc you are running.
So take the number of users and look at your disk count. A rule of thumb for 10K drives is 130 IOPS, 15K is 180 IOPS. Again..general rule and usable IOPS vary based on RAID type and Read/Write ratio. For a significant deployment we usually try and put the gold image on flash drives and the user specific delta set on FC or SAS drives. User profiles can go on SATA..and you need to look at how you are managing those profiles as they can easily kill you on performance.