73 GB disks "right sized" to 68000 MB (with zoned checksums..
anyone know if that's the same with block checksums?)
Since you can't use 14 disks and still have a spare, I'm doing
this with one seven disk set and one six disk set.
(68000 MB * 7) - 68000 MB (parity) = 408000
(68000 MB * 6) - 68000 MB (parity) = 340000
408000 MB + 340000 MB = 748000 MB
748000 MB * 0.9 = 673200 MB (lose 10% to WAFL)
673200 MB * (1 GB / 1024 MB) = 657.42 GB
So... that would be 657.42 GB usable, assuming no snap
reserve.
However, I think if you're buying a DS14 you'll get block
checksum disks, which might be right sized to a different size, in which case it
would be a different answer. :)
MD
----- Original Message -----
Sent: Thursday, December 13, 2001 12:35 PM
Subject: Real vs Raw disk space
Toasters,
We are
looking at purchasing some new DS14 shelves with 72 GB disks.
In order to
properly forecast our disk space growth, I was wondering if
anyone out there
had taken a look at the difference between real and
usable disk space
realized with these new shelves and drives.
Basically, our
environment is as follows: DS14 Shelf with 14 72 GB
disks (1 RAID group
of 8 disks, 1 RAID group of 6 disks), attached to a
filer running DOT
6.1R1P1. We will have 1 spare disk and no snap
reserve.
Geoff
Hardin
geoff.hardin@dalsemi.com