Re: RAID 5 Partitions

Robert W. Downard ( (no email) )
Sun, 26 Jul 1998 20:31:49 -0500

System Administrator wrote:
> 1. DO YOU NEED TO PARTITION THE RAID 5 STRIPE SET AS NTFS OR AS FAT?
> 2. WILL FAT OR NTFS PARTITIONED DRIVES WRITE TO A RAID 5 STRIPE SET
> WHICH IS EITHER FORMATED AS FAT OR NTFS [EXCHANGABLE]? AND DOES
> THAT EFFECT RECOVERY SHOULD A DRIVE GO DOWN?
> 3. ARE RAID 5 PARITY STRIPE SETS ASSIGNED A DRIVE LETTER OR DO YOU
> LEAVE THEM WITHOUT ANY?

A hardware RAID array appears to the OS as a single drive. This drive
can be divided into partitions just as any other drive can be. The type
of partitions you create have no impact on the recoverability of the
array because the recoverability is handled with the hardware, the OS
doesn't even know about it.

> 4. DOES IT MAKE MORE SENSE TO CREATE A RAID 1 MIRROR SET FOR THE C:\
> DRIVE. THE SAME FOR THE F:\FAT DRIVE PARTITION & WHAT'S LEFT OVER AS
> RAID 5 PARTITIONS.

Are you planning to purchase additional drives? To mirror C: and F: and
make E: a RAID 5 array, you will need 7 physical drives because the
arrays are created at the hardware level. A RAID 1 array requires at
least 2 physical drives and a RAID 5 array requires at least 3 physical
drives. I would recommend creating a single RAID 5 array, which, with
your 3 9G drives, would yield 18G of usable disk. You loose the
capacity of one physical drive for the redundancy. Partition this 18G
array into 4 partitions, C:, D:, E:, and F:.

-- Robert W. DownardNetworking & Systems Spec.      email:  downrw@sncac.snc.eduSt. Norbert College             Phone:  (920) 403-3971100 Grant Street                  Fax:  (920) 403-4084De Pere, WI  54115-2099