[rescue] Backups

[Jochen Kunz]

On Fri, 17 Jun 2005 15:23:05 -0400
velociraptor <velociraptor at gmail.com> wrote:

> I've never seen an LTO or DLT that was not wide SCSI, or Diff/Wide
> SCSI.
The DLT III / III XT (10/20 / 15/30 GB) drives are narow SCSI.

> I'd seriously doubt the ability of an x86 box
> with IDE drives to be able to provide the sustained output
> to necessary to keep a local SCSI DLT streaming--but I'm
> guessing.  Maybe SATA RAID-5?
I know of a file server with 40 GB WD IDE drives (software RAID 1), 300
MHz Pentium II and a DLT III XT that can keep the DLT most of the time
streaming. OS ist NetBSD 1.6, backup tool is the standard dump(8). I
have to admit that this box is nearly idle at backup times. I think
concurent access from NFS clients during bachup would kill performance.

My main machine at home is an Octane R12k 300 MHz, 9 GB and 18 GB UW
SCSI disks, DLT III XT dive and it can't keep the drive streming too. (I
use xfsdump(1M)) Before the Octane I used a 500 MHz Alpha EV56 with
Tru64. Same here. This machines, in particular the Octane, are capable
of carrying several metric IO butloads. But sometimes there are too many
small files that require too many head movements. The usual "disk seeks
are trashing throughput" problem.
--


tsch|_,
       Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/