Using SUN E450 (4x UltraSPARC-II 400MHz, 2GB RAM) QLogic 2200F, 1x 1GBit 
Ethernet, Sol8, NBU 3.4_2, Crossroad 4x50, SGT LTO Viper 200 HVD SCSI up to 
36MB/s single drive.

Same machine and FC HBA; native FC IBM LTO drive up to 43 MB/s single drive.

NUMBER_DATA_BUFFERS=32
SIZE_DATA_BUFFERS=131072

Measured by iostat during backup with massive MPX (from 10 to 12 Solaris 
clients usually full backup of /var)
Results depends on type of data and drive compression so much I think.


Vlastimil Pokorny


>From: "Fabbro, Andrew P" <Fabbro.Andrew AT cnf DOT com>
>To: Veritas-bu AT mailman.eng.auburn DOT edu
>Date: Thu, 11 Jul 2002 22:23:50 -0700
>Subject: [Veritas-bu] LTO Tuning (Research Results)
>
>Recently we deployed an LTO-based solution.  Out of the box, we saw an
>anemic 5MB/sec performance on the drives.  Veritas did not provide much in
>the way of suggestions for tuning, so I had to do it myself.  
> 
>The attached .zip file (necessitated by this list's 20Kb limit) contains:
> 
>- a text document that describes the hardware configuration, tuning, and
>conclusions
> 
>- an Excel 95 spreadsheet showing the NUMBER_DATA_BUFFERS/SIZE_DATA_BUFFERS
>cases I ran to come up with good performance.
> 
>Enjoy (and I would love to compare notes with anyone else using LTO).
>-- 
>Drew Fabbro 
>fabbro.andrew AT cnf DOT com