Attaching high performance RAID 1 drives to VM for database.

[theonlylawislove]

I want to host a VM that will act as a database. I want to know how to efficiently configure the virtual to get maximum read/write to the RAID 1 drive (2 mirrored).

My setup:
3 harddrives.
1 - OS/Host
2/3 - Raid 1 mirrored, will store the VM virtual disks for the guest OS.

Should I just create large virtual disks for the VM, and store my data in it (since VM guest is on RAID 1)? Or, can I create a "/Data" drive on my host, and share this folder to the VM and configure my database to store data in it? Is that even possible? If so, which is more performant?

My thought process is that managing a large amount of data may have additional overhead when this data is managed within a virtual disk. If so, should I (can I?) just mount a \Data folder from my host into my VMs?

[scottgus1]

If "create a "/Data" drive on my host, and share this folder to the VM" means to use a folder on the single drive that's not in the RAID 1, it is possible, but keep in mind the data will not be mirrored, and if the host OS drive dies, your data dies.

Other than that, the only way to test speed is to try. You do have some overhead translating the guest OS drive saves through the host to the disk. You also have overhead saving through a shared folder to the drive, whether the single or the RAID. Which one takes more time is best handled by your own experiments.

If you have or can get a motherboard that has enough ram you can use a ram drive as your database processing disk. Lightning-quick loads & saves, even though virtual disks. I've used Dataram (http://memory.dataram.com/products-and- ... re/ramdisk) on my Windows hosts and have had good results running a guest with a second virtual disk on the ram drive. (No I don't work for them ) Need to have a stable host, a good UPS, and an online backup routine in the guest when using a ram drive, though.

SSDs will get faster access times than platter drives. Our SBS2003 guest took 5 minutes to boot on a platter drive RAID 1. We moved it to an SSD RAID 1. It now takes a minute and a half to boot.

[BillG]

Ben Armstrong from the MS Hyper-V team posted an article on disk drive speeds just a few hours ago which might be of Interest.

http://blogs.msdn.com/b/virtual_pc_guy/ ... s-are.aspx