RAID 5 ???

[21stHermit]

Researching RAID, I found out I need 3 HDs to implement RAID 5.

. . Can I scale up over time? Add more HDs as needed? What are the consequences?

. . Does the 3 - HD RAID 5 array look like a single drive letter to Win XP?

. . If I start with 3 - 250GB SATAs, how much space do I get for storage?

Thanks,
Hermit

 

[RedCOMET]

I think you want this in General Hardware.

Unless your are talking about file server or other network connected storage device, then this might be the place for you.

Edit:
Both are some good links for info on raid.
If you search the Forums here, in GH and maybe OS, you shoudl find some threads about raid setups and peoples problems with them.

AT Raid FAQ

Storage Reivew RAID Guide.

 

[networkman]

Originally posted by: 21stHermit
Researching RAID, I found out I need 3 HDs to implement RAID 5.

. . Can I scale up over time? Add more HDs as needed? What are the consequences?

Depends on the controller being used, but generally speaking no, you may not simply add more drives as needed, since the available space in the array is defined as N - 1. You could of course backup the data, define a new array of N drives and restore to the new array.

. . Does the 3 - HD RAID 5 array look like a single drive letter to Win XP?

Yes.

. . If I start with 3 - 250GB SATAs, how much space do I get for storage?

(N - 1) = 500 GB

 

[Crusty]

If you are using a decent hardware controller you can expand RAID 5 volumes on the fly. Then just use partition magic to expand your partitions if need be.

My dad just recently expanded his 4x120gb SATA raid 5 array to a 6x120gb SATA raid 5 array using an LSI MegaRAID controller.

It was very easy.

 

[thriemus]

RAID 5 is good for reading info and data redundancy but it suffers when writing information. My raid 5 array reads at 90mb/sec which is great but only writes and 20-30 mb/sec which is slower than a single drive because of the parity. I would recommend raid 10 if you going to be writing alot of data to the drive (which yes shows up as 1 drive in explorer) Raid 10 means you will need a minimun of 4 drives and you get half the storage, EG 4 x 250Gb drives in raid 10 array = 500 GB drive mirrored and striped, and fast reading and writing.