I am looking for some opinions/education on utilizing my XPS 600 with RAID. The general questions is this: Can you set up a 3 drive system with 2 (1 TB) high speed hard drives striping(i.e. Western Digital Black) RAID 0 (So a total of 2 TB) with a RAID 1 - 2 TB slower Hard Drive(i.e. Western Digital Green)? Is this possible? Is this not good practice? Can you accomplish the same effort by having three identical drives and using striping across the three? I believe my only options on this box is RAID 0 or 1.

Dlustri,

No, you won't be able to create a RAID 0 with the two of the drives and then, create a RAID 1 between that RAID volume with another drive.

You can stripe across 3-drives with RAID 0; but in cases like the one you stated (2x 1TB drives and 1x 2TB drive), your RAID 0 will stripe across all 3 drives but only across 1TB on all drives. Think of Lowest Common Denominator. Your RAID 0 volume would have 3TB of usable space in your example. A RAID 1 will only ever use 2 drives; but it gives you redundancy against drive failures. RAID level choice depends on if you need capacity and performance or if you need redundancy.

Thanks for your help. A follow up question would be this, if you have a two drive RAID 1, but one drive is slower than the other, does this drag down the speed of the faster driver? What I mean is, can I place a faster drive as my primary (i.e. Western Digital Caviar Black) and use a slower drive like the (Western Digital Caviar Green) as the 'redundant' drive and not lose the performance of the Black hard drive? They are both 2 TB. I'm not fully versed in the 'how it works' when writing the data in RAIDs. Is there a queue for the second 'redundant' drive that gets written to as processor time becomes available or is it hard wired to write immediately and at the same time as the first drive. thanks again for your help.

In my experience, the RAID 1 will step down to the lowest common rpm of your drives. When you write to the RAID 1 volume, the IO won't complete until it has finished writing to both disks and when you read from the RAID 1, you can read from each of the mirrored disks. But in order for the data to be consistent end-to-end, it cannot read/write more data from/to your faster disk and less from/to your slower disk so the firmware matches up the disk rpm to the lowest common rpm to maintain this consistency.

Unfortunately, there is no other queue for the redundant drive- on writes it will be to both drives in a RAID 1 at the same time.