Rainer Mager wrote:
>
> Hi all,
>
> I have a motley set of disks that I'm hoping to use more effeciently via
> raid. Any tips on this would be greatly appreciated.
>
> Right now I have:
>
> 2 X 2 Gig SCSI
> 1 X 3 Gig SCSI
> 1 X 7 Gig SCSI
> 1 X 4.5 Gig UW SCSI 2
> 1 X 20 Gig IDE
>
> I don't know the exact type of SCSI for the for 4 drive but they are all old
> and slowish. The 4.5 Gig one is nice and fast and is on a dedicated 40 MB
> SCSI bus right now. Also I have 1 128MB partitions taken out of each drive
> that I use for swap, yes, I know that gives me 800 MB swap (yummy).
>
> I know I could combine all/any of the drive using Linear-RAID but I really
> want some redundancy. I believe that probably puts me in the RAID-5 area.
> The problem is all of the disks are different sizes.
>
> I was thinking of trying to create something like a 3 slice size for the
> RAID array. I would take one out of the 3 Gig, the 7 Gig, the 4.5 Gig, and 1
> or more out of the 20 Gig. I would also combine the 2 X 2 Gigs into a 4 Gig
> (using RAID-0) and then take a 3 Gig out of that. Then I would have at least
> 5 3 Gig pieces that I would combine with RAID-5. I would probably use the
> other half of the 7 Gig for a backup to that array and perhaps the same via
> another slize of the 20 Gig.
>
> Any comments? Can I use a RAID-0 disk in a RAID-5 array? Is this a good or
> bad idea?
Sounds like a decent idea, although I don't know if it will work. The
docs (info pages maybe?) say clearly which RAID levels can be "stacked"
as you describe. One of these days I'm going to get a nice big DLT (as
soon as that server isn't need anymore... can't wait), and ignore disk
redundancy and go with backups. RAID5 tends to be somewhat messy no
matter what happens because of the way that it works. Give it a shot,
and let us know what happens.
Greg
