Come somebody explain RAID?
- Thread starter phi1
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I see from your signature you have a Gigabyte DS4, the onboard controller allows for Raid0 (striping), Raid1 (mirroring) and Raid5 (block striping with parity data written across the drives - needs a minimum of 3 drives).
Raid0 is the fastest of the options but allows for no redundancy so if one drive goes down then the whole thing is done for, it also doesn't benefit everyone in speed terms as it works best for large contiguous files.
Raid1 is safer as you have an exact copy but doesn't tend to improve speeds at all.
Raid5 is relatively safe and can cope with the loss of one drive and allow the array to be rebuilt however it isn't particulary fast for writes I believe although read speeds are good.
There is way more information in a Wikipedia article for instance but I've just given you the very quick overview.
Raid0 is the fastest of the options but allows for no redundancy so if one drive goes down then the whole thing is done for, it also doesn't benefit everyone in speed terms as it works best for large contiguous files.
Raid1 is safer as you have an exact copy but doesn't tend to improve speeds at all.
Raid5 is relatively safe and can cope with the loss of one drive and allow the array to be rebuilt however it isn't particulary fast for writes I believe although read speeds are good.
There is way more information in a Wikipedia article for instance but I've just given you the very quick overview.
semi-pro waster said:I see from your signature you have a Gigabyte DS4, the onboard controller allows for Raid0 (striping), Raid1 (mirroring) and Raid5 (block striping with parity data written across the drives - needs a minimum of 3 drives).
Raid0 is the fastest of the options but allows for no redundancy so if one drive goes down then the whole thing is done for, it also doesn't benefit everyone in speed terms as it works best for large contiguous files.
Raid1 is safer as you have an exact copy but doesn't tend to improve speeds at all.
Raid5 is relatively safe and can cope with the loss of one drive and allow the array to be rebuilt however it isn't particulary fast for writes I believe although read speeds are good.
There is way more information in a Wikipedia article for instance but I've just given you the very quick overview.
thanks, Thats made it a bit easyer to understand.. So is it possible, to get another 3 off the same 200gb hds i already have.. And then 1x 500gb or somthing for storage?
3 more drives would be pointless for anything other than RAID5 (or you could go RAID0+1, stripe + mirror).
RAID0 with 3 or more drives is very unlikely to outperform a pair of disks due to limitations of the PCI bus, and RAID1 with 3/4 drives is pointless unless you expect 2 or 3 disks to fail at once.
Also, RAID5 has very slow write speeds (coupled with high CPU usage) when using onboard controllers, so I'd strong suggest not using it as a boot volume if you decide to go RAID5.
The best option would probably be 4x200GB in RAID5 for storage and a decent drive like a Seagate 7200.10 for boot as then you have a fast system disk and decent redundancy on your storage volume (1 disk can fail and you can rebuilt the whole array). You lose a bit of space though, if n = number of disks and c is the capacity of the smallest disk, the usable space is (n-1)*c, so in this case (4-1)*200GB = 600GB.
Remember that RAID doesn't protect against user error or corruption/viruses though.
RAID0 with 3 or more drives is very unlikely to outperform a pair of disks due to limitations of the PCI bus, and RAID1 with 3/4 drives is pointless unless you expect 2 or 3 disks to fail at once.
Also, RAID5 has very slow write speeds (coupled with high CPU usage) when using onboard controllers, so I'd strong suggest not using it as a boot volume if you decide to go RAID5.
The best option would probably be 4x200GB in RAID5 for storage and a decent drive like a Seagate 7200.10 for boot as then you have a fast system disk and decent redundancy on your storage volume (1 disk can fail and you can rebuilt the whole array). You lose a bit of space though, if n = number of disks and c is the capacity of the smallest disk, the usable space is (n-1)*c, so in this case (4-1)*200GB = 600GB.
Remember that RAID doesn't protect against user error or corruption/viruses though.