You did: dd if=/dev/zero of=/dev/nst0 bs=1M and different mt setblk Since tape drives can compress data, /dev/zero is a bad source of data, since it compresses real good. /dev/urandom is a better source.
You would like IBM's LTO-2 tape drive. It does 35M/s! They claim the LTO-3 does 70M/s! Guy -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gerhard Schneider Sent: Wednesday, March 02, 2005 5:30 AM To: Kai Makisara Cc: scsi Subject: Re: 2.6.10-rc4 tape slow after switch Fusion MPT to Megaraid On Sun, 2005-02-27 at 22:46 +0200, Kai Makisara wrote: > > This shows that your application is not using very large block size (3 > pages, 10 kB?). You might get better throughput with larger block size (32 > kB or 64 kB is usually large enough). If the Megaraid command processing > speed is not fast enough, this might explain the problem (not probable but > I can't see any probable problems ;-) > After different tries (I had problems w/ my backup schedule - ever tried to back up 600 GB with 2.6MB/s? :-) Tape block sizes between 10k and a few MB don't make any difference For better understanding I did the tests with dd if=/dev/zero of=/dev/nst0 bs=1M and different mt setblk No chance to go above 2.6 MB/s Gerhard Schneider -- Gerhard Schneider Institute of Lightweight Design and e-Mail:[EMAIL PROTECTED] Structural Biomechanics (E317) Tel.: +43 1 58801 31716 Vienna University of Technology / Austria Fax: +43 1 58801 31799 A-1040 Wien, Gusshausstrasse 27-29 http://www.ilsb.tuwien.ac.at/~gs/ - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
