Questions arising from the Big WHS blog - RAID types and

[swinster]

I have just read and caught up on the Big WHS blog, and posted a couple of comments in the last post. Patrick asked if I could post in the forums, so here we are. Not sure if this is the best forum, but its a start.

Hey Patrick. I have just read through all your blogs concerning the Big WHS. Whilst my plans aren’t anywhere near as ambitious and my hardware pales into insignificance against that shown, I am in the process of at least adding more drives and RAID options.

At the moment I have a simple Adaptec 5405 with 4 x 1.5 TB Samsung drives as a RAID 5 array, with a 2 WD drive as RAID 1 for the OS on the MB controller and a third as a spare. I run Win 2003 SBS rather than WHS, but this is something I am looking to change, however, I do run Exchange and various test SQL databases and websites. Also, I have been toying with the idea of virtulises this (either the current OS, WHS or SBS 2011) and add multiple VMs using ESXi, such as MythBuntu and an Asterix machine.

I’m not as informed as you with regard to all of this and I noted that you have used VM for various software RAID and NAS machines. What would the purpose of using a software based RAID device as well as hardware RAID? How have you got your drive actually configured in arrays, and what RAID version do you find most acceptable for which purpose?

One other point. I have read (no idea where now), that actually running RAID/NAS OS systems as VM is not that brilliant and that they do not behave always as expected. How have you found this in your setup.

Further to these questions and the idea of virtulisation, one might as well ask what does, or what doesn't, make for a good system to virtualise.

 

[Patrick]

The main reason for using software RAID is that you can scale beyond eight drives in a very cost effective manner (I spend about $12/ drive) and you can get some cool features with ZFS and etc. The big thing here is you basically need to have Vt-d and a controller that exposes disks directly to the OS. Probably the big thing you want is Vt-d or IMMOU (on the AMD side) because that passes the controller to the VM OS.

The 5405 is still a great card if you already have it and I find HW RAID easy to manage. If you can afford to, I would suggest at least playing with ESXi or Hyper-V server with non-production drives.