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Old December 15, 2007, 02:33 PM
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Jack Rabbit Jack Rabbit is offline
Join Date: Sep 2007
Location: Toronto, ON
Posts: 784

My System Specs


I think running the OS off a 5400 RPM drive would be bad. I can feel the difference between the different drive speeds.

RAID is not a backup solution and, based on your description, not the best option for you. RAID for performance is a good idea for the consumer but RAID for redundancy is not there. Yes, if one drive fails your data is not lost yet but the real industry drive for this is to speed recovery time from a hardware failure. How much does it cost in lost revenue or productivity to have a server or workstation down for a day while it is rebuilt? If that is more than the coast of the RAID then put in a RAID. If all you want is a good back up solution I suggest buying a good backup software and backing store (or research the free alternatives). Just make sure it is automated and does not allow you to have 3 month gaps in the backup schedule.

A lot of the things that are likely to destroy your drives are likely to wreck the whole system at once. A colleague of mine had some electricians working on the house and they manage to do something wrong and most of the hard drives in the house were destroyed. The only ones that survived were the ones not plugged into the wall at the time. Ditto for a flood. Ditto for accidentally deleting the wrong folder and losing all your stuff. A friend of mine just used RoboCopy wrong and lost 60G of data; /MIR is dangerous!

RAID 5 will not give you a speed boost. Something has to do all the math to generate the parity data and that is usually the CPU unless you sped a lot of money on a real hardware RAID card. RAID 1 just write the same thing to the two disks so it is about the same speed as one drive.

What ever you get make sure you test out how to rebuild the system before you have a drive die. Consumer level RAID systems are not very smart. Even though SATA can be 'hot plug' many implementations do not support this feature. A drive seizing up may very well take the whole system down with it as the drivers just can not cope. Do not trust the driver or specs.

Another big disadvantage for the consumer with RAID 5 is that the disks are useless on their own. Sure, if one goes you can replace it but the chances are that box will run for a couple years at least. In two or three years where are you going to get a replacement for that bread of drive? If you can find one at all it will probably cost more than a single drive that is larger than the whole RAID. With a mirror, you can put a drive in any computer or disk enclosure and get the data off it very easily.

If you decide to go with a RAID solution I suggest putting those two 250s into a mirror (RAID 1) for your data. It will be faster than RAID 5 and easier to recover from in case of a failure.
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