Veritas-bu

[Veritas-bu] Where in NBU are drive settings (LTO-1 and LTO-2) tuned separatel y?

2003-12-05 07:25:46
Subject: [Veritas-bu] Where in NBU are drive settings (LTO-1 and LTO-2) tuned separatel y?
From: william.d.brown AT gsk DOT com (william.d.brown AT gsk DOT com)
Date: Fri, 5 Dec 2003 12:25:46 +0000
There are no separate tuning options for different drives apart from in 
the st.conf.   Do make sure you have the right entries for the two types 
of drive.  I don't have them but the LTO-2 entries have been posted to 
this list.  So mixing drive types on a media server means you have to 
compromise about block size & buffer count.

The most likely problems are (1) your disks are not as fast as you think 
at sequential access.   Use some of the tools from the HP web site for 
this - dig down near their LTO drive and you will find tools to test disk 
& tape.  (2) You are not providing data fast enough to bptm, i.e. even 
your LTO 1 drives are not beign driven fast enough.   Either play with 
buffers or increase multiplexing.




William D L Brown


veritas-bu-admin AT mailman.eng.auburn DOT edu wrote on 04/12/2003 20:07:35:

> NBU 3.4.1 Master:HP-UX 11i three-way service guard cluster Library:
> ADIC scalar10k IBM Ultrium drives:[email protected], [email protected] same cabinet. 
> We have just benchmarked our new LTO-2 drives and they are NO FASTER
> than the LTO-1 drives. Are there separate tuneables for the new 
> drives we are not looking at?  Buffer settings, something 
> undocumented perhaps?  We have a 3GB (bound) FC ethernet connection 
> on the media server so I don't think it's a network bottleneck, disk
> is XP-512 (rebadged Hitachi) screaming fast disk.  Tested same class
> on each type of drive, identical runtimes. ??? Thank you experts.
>      Aren M. Parisi Ò 
>  Information Technology 
>   Western Wireless Corp. 
> (425)313-5225 mob.(206)795-6631 
>  Where are we going and why am I in this handbasket?