[X-Unix] Hardware RAID Setup

[Martin McCormick]

Stroller writes:
> Like I say, never used RAID on Macs, but a little bit on Linux now (with 
> at
> least 3 different controllers).
> 
> 
> 
> When you initialise the array it will wipe out any data on the disks. The
> long wait you mentioned was the drives zeroing out. After the
> initialisation is completed, the two drives of a RAID1 array will always
> (in normal use) contain identical copies of data (subject to the 
> completion
> of writes on each).
> 
> 
> 
> The initialisation will (surely) NOT mirror existing data to an array
> during creation, although some RAID controllers / userspace utilities 
> offer
> a "migrate" command.
> 
> 
> 
> What you could do, for instance, if you have a working installation of
> MacOS on drive A, is to build an array Z from drives B & C. Then dd from A
> to Z. I have undertaken some variations of this under Linux; depending 
> upon
> the complexity of what you're undertaking it can be either very easy and
> straightforward or time-consuming and somewhat harrowing.
> 
> 
> 
> You will likely only be able to use the drives when connected to the
> controller - i.e. you cannot remove one drive and read it on a different
> computer, unless that machine has the same RAID controller. If one drive
> fails you will be prompted to replace the drive - you should be able to
> work with only the single drive in the meantime. After you replace the
> failed drive the array will be rebuilt (copied, effectively) onto the new
> disk, and again you should be able to use the system during this rebuild
> process (disk operations will be slowed, as your use of the disk is
> effectively "shared" with the rebuild).

	This sounds like what the documentation I have been
reading was saying. I guess I will go ahead and see if the disk
utility will format it and maybe I will get a usable device out
of it. Once that happens, it should work as the raid card,
itself, seems to be satisfied.

Martin McCormick