[CentOS] Problems with LTO-3 and U320 on Centos 4.4

On Wed, 8 Nov 2006, Wojtek.Pilorz wrote:

> On Wed, 8 Nov 2006, Joshua Baker-LePain wrote:
> 
> > Date: Wed, 8 Nov 2006 07:43:23 -0500 (EST)
> > From: Joshua Baker-LePain <jlb17 at duke.edu>
> > Reply-To: CentOS mailing list <centos at centos.org>
> > To: CentOS mailing list <centos at centos.org>
> > Subject: Re: [CentOS] Problems with LTO-3 and U320 on Centos 4.4
> > 
> > On Wed, 8 Nov 2006 at 12:21pm, Adam Huffman wrote
> > 
> > > Apologies for hijacking the thread, but I'm seeing speeds of only around
> > > 30MB/s with an LTO3 library connected via 2Gb fibre channel, both with
> > > tar and with Bacula.
> > >
> > > Would you know how to go about investigating this?
> > 
> > What blocksize are you using?  That has the biggest impact on tape 
> > performance of any of the factors I've looked at.
> > 
> > 
> I had some experiences with much slower systems (both tapes, connections 
> and CPU/memory) when to get any performance close to rated tape speed, I 
> had to use buffering (there was buffer utility); I guess -fifo feature of 
> star should be looked at.
> 
> Wojtek
> 
> 
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I've been able to push a single LTO2 tape to 93-96MB/s and single LTO3 
tape to 137-139MB/s.  Note, the drive is an HP-Ultrium2-SCSI and 
HP-Ultrium3-SCSI and nothing else was connected to the SCSI bus.  I used 
NetBackup to perform the tests with various levels of multiplexing.

Justin.