Disk requirements for 13-14 VMs

[hellosky]

On my new server I expect to run about 13-14 VMs. Most of them will be idling but two VMs might use a good chunk of resources (these two will handle application deployment, software updates, and OS imaging).

To ensure that all VMs run at a reasonable speed, what kind of disks should I get? For now I am thinking about this (limit of 8 drives on this server).

4x RAID 10 with WD RE4 500GB drives to host hypervisor and the VMs
4x RAID 5 with WD WD20EADS drives to store the software update/application files and the OS images, as well as movies/TVs and personal documents

Will this be OK or should I run 8 drives in RAID 10 and store the other files on a new machine?

 

[dhahlen]

How much space do you actually need? Raid 5 versus Raid 10 will yield you approximately ~2TB. For solid read/write performance, RAID10 is going to be your best bet. It offers better redundancy as well as speed, at the cost of space. I'll usually have my VM-Host running a Mirror setup with 146 15k, and then use a RAID10 array for VM storage and data. If you want the space, go raid 5.

Some suggestions:

-Use smaller Array (2 disk) as Raid1 for VM-Host
-Use Larger Array (6 or 8 disk) as Raid10 for VM-Host and Data
-Use Smaller Array (4 disk, 500gb) as Raid 10 for VM-Host
-User Larger Array (4 disk, 2tb) as Raid5 for Data

Like I said, if your goal is capacity, you may want to do Raid5, throw in a hot spare later if you can. I've set up VM's where the smaller array hosted the VM itself and the larger array was for data storage (fileservers, etc).

Given you have 8 disks, I would run a Raid1 (2 disks) for the VM-Host machine. I would then take the remaining 6 disks (assuming they're all 2tb) and run a Raid10 for storage. Your alternate option would be to run a Raid10 (4 disks, 500gb), and a Raid5 (4 disks, 2tb), and host the VM's on the Raid10 while using your Raid5 for data.

I've probably said the same thing 10 times, but you get the idea.