perc6i RAID problems with drives greater than 1 TB

I had an interesting problem I think that deserves and honourable mention in the frustration category – partly because it’s not mentioned by many online in a clear way and it’s hard to find the real answer.  For anyone having this problem – here’s the answer, tip jar is to your right :P

I have a Dell R410 with a H200 RAID controller – that controller is a bust, it initializes disks slowly and takes F.O.R.E.V.E.R, don’t get this controller!  Return it, and get the H700 (don’t cheap out like I did!)

I then upgraded to a Dell perc6i – I’ve had some experience with those and they’ve always been solid.  Again, if you have over 1 TB disks and need a RAID10 buy the H700 instead now!

The problem:

So here’s the problem with the perc6i’s – this is from the manual:

NOTE: For RAID levels 0, 1, 5, and 6 only, you can use part of the available disk space to create one virtual disk and then use the rest of the disk space to create another virtual disk or disks.

I wanted my disks in RAID10 – they are 2 TB SATA disks.  Great but when you make the RAID volume (virtual disk) it creates a 4 TB (give or take) virtual disk – that’s all you get, you can’t customize how many virtual disks you have or their sizes, you get 1 at 3.9x TB.  Great however, if you’re putting Windows on it IT WON’T WORK!  Why?  Because you have to put your boot volume on this 4 TB disk but Windows only lets you have a boot volume for Windows on a maximum 2 TB disk / volume.  The rest of the space is all wasted and I don’t think you can use diskpart to fudge it either, it errors out.

http://technet.microsoft.com/en-us/library/cc773268%28v=ws.10%29.aspx

You can do everything you want to do if you use RAID5 but I want to use RAID10 you’re out of luck.  The solution is to upgrade your controller to the H700 which can indeed allow you to make 1 – RAID10 container with quantity 4, 2 TB disks for a total RAID10 container of 4 TB THEN THEN THEN you can create virtual disks in that container of say 120 GB for your OS boot volume and have another separate virtual disk with the rest of the space for your data volume.  There’s another “problem” that I also bumped into online and that would be the use of disks OVER 2 TB (or maybe it was 3 TB).  That has to do with what the firmware can handle from a bit level – a 32 bit firmware can only handle 2 TB of storage where a 64 bit firmware can handle far more than that SO if you have 3 TB disks…I’m not sure the H700 will work for you, you’d want to make sure from Dell your controller can handle the size disk you’re using.  I don’t have specifics on that but I’m aware of this other problem.

See the “NOTE” above that says you customize your vitual disks in RAID levels of 0, 1, 5 and 6 “only” to have multiple virtual disks in a RAID container – again, I’m trying to do RAID10 so the perc6i won’t work because it only gives you the 1 container option with only 1 vitual disk you can’t modify :-(

I did find another blog online that tipped me off to this but he was using RAID5 so he fixed his problem by redoing his virtual disk setup.  His “fix” wasn’t really a fix for me but it turned the light bulb on in my head.  That blog is the first in my references list.

References:

http://t-solve.blogspot.com/2010/06/unable-to-allocate-drive-space-for.html

http://stuff.mit.edu/afs/athena/dept/cron/documentation/dell-server-admin/en/Perc6i_6e/chapterb.htm
* Of note are things that say:  “One virtual disk per disk group for spanned RAID levels: 10, 50, and 60”

http://technet.microsoft.com/en-us/library/cc773268%28WS.10%29.aspx