On 7/11/05, Michael A. Coan <mikecoan@woodlawnfoundation.org> wrote:
My plan is to use RAID 0 (I know that means no redundancy) and then use an additional hard drive for backing up the data files.
RAID 0 is striping and will give you extra speed. But RAID 0 has the huge drawback if one drive fails, the whole thing comes crashing down, and you'll have to reinstall everything.
I realize that. I guess my initial thought was tht it is very easy to reinstall SuSE 9.3 (less than an hour). Since Windows server will be a guest OS, it will only be 6 or 7 files, so I copy over the files in 10 minutes and it is reinstalled. I figured that the time saved by using RAID 0 over say three years, would more than offset the time it takes to reinstall. Maybe that is foolish.
I would avoid RAID 0 if you can. Unlike the other RAID levels, with RAID 0 the more drives you have in the array, the more unreliable it is!!! ie. if your drives have an average life of 3 years then: Single drive: 50% chance of failure in 3 years ( 1 - .5 ) Two drive RAID 0: 75% chance of failure in 3 years ( 1 - (.5 * .5)) Three drive RAID 0: 87.5% chance of failure in 3 years ( 1 - (.5 * .5 * .5)) etc.
Maybe i should use a 3ware controller and do raid 5. this time I will know what the beeping is :) Or would you recommend RAID 10 instead.
RAID 10 is the fastest and most reliable, but also the most expensive. Especially on writes RAID 5 can be very slow, but the more drives in your RAID 5, the faster it should be.
i am not inclined to use raid 5. Our current server had raid 5 with a Perc controller and 3 Ultra 160 SCSI drives. When one of the drives failed the controller began beeping like crazy, but everything worked Too bad i didn't know what the beeping meant. By the time I figured out what the beeping meant, a second drive failed and I had to reinstall Windows Small Business Server on the remaining drive.
I think Linux MD now supports RAID 6, or maybe that is some specific hardware controllers. Not sure. RAID 6 is like RAID 5, but it has 2 parity drives. In the above you still would have been okay until you lost the 3rd drive. Personally, I would not consider RAID 6 unless I was planning on having 6 or 8 or even more drives in the RAID set. With less than that you might as well use RAID 10. Greg -- Greg Freemyer The Norcross Group Forensics for the 21st Century