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Old August 15, 2010, 05:29 PM
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lcdguy lcdguy is offline
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well almost all the time hardware raid is superior to software raid. regardless of the raid level but more so when using raid levels that use parity (5, 6). as for which raid level it all depends on how much space you want use and how important the data is. the most common raid levels are 0, 1, 10, 5, 6

raid 0 - striping, putting all your drives into one big array. huge speed boost but lose a drive and the data is toast.

raid 1 - mirroring, duplicates data across 2 disks at the same time. performance is not great. but data integrity is awesome

raid 5, 6 - striping with parity, this is a compromise between data safety from drive failure and decent performance. however for this to be useful you must use a hardware controller. with raid 5 you can lose 1 disk with raid 6 you can lose 2. you also lose a drive worth of space to the parity.

raid 10 - mirroring and striping, for this you first need even numbers of disks in your array. you also will only have 1/2 of the total storage available to you. gives great performance for random IO and good protection from drive failure. also there is no parity so the overhead is low.

i would also consider WHS as an option as it doesn't use raid, it allows you to mix and match drives and provides folder duplication so when a data file is written to one drive in your array it is copied onto another drive.

but if your set on getting a good nas with 8-10 drive capacity this is what i would recommend.

raid card - look for a second hand perc 5i or 6i unless you have a couple hundred dollars to spend on a controller.

case - i'm a fan of rackmount stuff so a norco rpc450 case
drive caddies - supermicro 5 in 3
NAS OS - freenas or openfiler

if you have a higher budget say around the 2500-3k mark i would look at a SAS card and a supermicro 846 series chassis as it supports 24 drives over a SAS cable.

another thing to keep in mind with raid is some of the non raid edition drives have a feature called TLER enabled which can break arrays which was one of the other reasons i went with WHS.
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