[5294] in linux-scsi channel archive
Re: DAT trouble
daemon@ATHENA.MIT.EDU (Jon Lewis)
Sat Dec 5 05:34:00 1998
Date: Fri, 4 Dec 1998 14:08:17 -0500 (EST)
From: Jon Lewis <jlewis@inorganic5.fdt.net>
To: Pete Popov <ppopov@redcreek.com>
cc: Linux SCSI Mailing List <linux-scsi@vger.rutgers.edu>
In-Reply-To: <366827C8.C9F17AD7@redcreek.com>
On Fri, 4 Dec 1998, Pete Popov wrote:
> The lower than expected performance is most likely due a small SCSI transfer
> size. I increased the default 32K to 128K, recompiled the st driver, and use 128K
> with tar and regularly get 70MB/s with my SDT-7000.
Since I got around half the advertised speed, I just started wondering if
maybe I'd accidentally done the backups with compression off...but I
double checked, and my script did have mt set compression on.
> The 1.5MB/s (90MB/min) spec is the actual transfer rate to tape. You'll
> need an extremely fast host with low SCSI command overhead to get close
> to that.
The system used as the tape host is a lowly P100, but does have a nice new
Diamond Fireport 40. Maybe it just can't keep up.
----don't waste your cpu, crack rc5...www.distributed.net team enzo---
Jon Lewis <jlewis@fdt.net> | Spammers will be winnuked or
Network Administrator | nestea'd...whatever it takes
Florida Digital Turnpike | to get the job done.
______http://inorganic5.fdt.net/~jlewis/pgp for PGP public key________
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.rutgers.edu
