scsi raid geometry high-point rocketraid 1640
jerrymc at msu.edu
Mon Apr 30 14:07:40 UTC 2007
On Mon, Apr 30, 2007 at 09:54:04AM +0200, Klaus Friis Østergaard wrote:
> 2007/4/30, Jerry McAllister <jerrymc at msu.edu>:
> >> Hi,
> >> I have a raidcontroller high-point 1640 with 4 disks of 400 GB in a raid
> >> array given me 1200 GB. The bios utility of the controller zero build
> >> array with 64 kb
> >> FDISK says that the geometry is 145923/255/63 and it is incorrect. Then
> >> says that for scsi it is the translation mode the raid controller is
> >Usually you want to accept what fdisk does. Just make the slices
> >that you want. Geometry is virtual on these systems.
> >> How do I find this?
> >> If I continue with the defaults I only get 1144654 MB like missing 100
> >Well, I would expect you to get something less than 1,490 GB just from
> >the difference between the manufacturer use of GB (1,000,000,000 Bytes)
> >and the way the OS uses GB (1,073,741,824 Bytes).
> That is the missing link, the raid controller says 1200 GB if recalculated,
> using 1.073741824 it gives 1,117.59 GB multiplied by 1024 it gives
> 1144409 MB which is what FDISK gives default.
Wow. Don't tell me I got one (out of how many?).
I shall celebrate.
> I don't know how much the raidcontroller eats up to manage
> >the raid. Raid 5 takes a piece for its redundancy/error
> >correction. A raid 5 would eat at least 20% and maybe up to 30% if it
> >is rather inefficient.
> WIth 4 disks it is 25% as 4th disk make the redundancy.
> After that you will lose some because of inconvenient remnants of space
> >that doesn't get used. Then, there are amounts for superblocks and other
> >aspects of building a filesystem, etc. I think that tends to be around
> >So, your number seems somewhat probable, offhand, without detailed
> >What operations did you do to get to that point? Mine would be an
> >fdisk that makes one slice of the entire device, a bsdlabel that
> >divides the slice in to about 6 partitions (including swap) and
> >a newfs on each partition except swap.
> I only need the array only for one big slice and one partition for data
> Thanks for the help
> Klaus F. Østergaard, <farremosen(at)gmail dot com>
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