I purchased the Dell MD1000 15 disk Direct Attached Storage Array in November. The enclosure itself is a JBOD system (Just a Bunch of Disks) because the controller inside does not support RAID. The RAID functionality of the system is achieved through implementing a PERC 5/e or 6/e controller in the server itself. The MD1000 can be daisy-chained for a total of three units supporting 45 disks. The MD1000 has dual controllers and dual power supplies for redundancy – something that should be expected in an expensive (albeit inexpensive in enterprise terms) product.
I have it hooked up to a PERC 5/e dual SAS (x4-type external) controller that supports RAID 0, 1, 5, 10, 50. Dell says you can configure the controller through pressing CTRL-R after the BIOS, but the tools are lackluster at best. Be sure to download Dell’s OpenManage system.
Below is my final configuration for my database and file server.
- 1 – “hot-spare” 73GB (SAS 15K Seagate)
- 4 – RAID 10 – 73 GB (SAS 15K Seagate)
- 10 – RAID 10 – 750 GB (SATA 7.2K Seagate)
- 2 – “cold-spare” 750 GB (SATA 7.2K Seagate)
Why not RAID 5? I don’t want the write-penalty that RAID 5 comes with, especially on a database server with the 4 SAS drives. The SATA array is cheap enough at $160 CDN per 750GB drive.
Overall I am satisfied with the system. The main concern was reliability. When a friend of mine brought up the fact that he could have done it less expensively with a computer in a large case and a bunch of drives, I agreed. With the MD1000 you get dual controllers, dual power supplies, and the ability to connect to two servers, which also helps if you are in a cluster. If you need network storage, definitely get a SAN array (not to be confused with NAS).
I have a decent crop of benchmarks of the test system before I finalized my configuration. I’ll post it later today once I get to a computer with Excel (or OpenOffice) to do some graphs.