An LTO-3 runs at 80MB/s native and will speed match down to 40MB/s
An LTO-2 runs at 40MB/s and will speed match down to 19MB/s
Below these rates the drive stops.

If your seeing 143.5MB/sec then it compressed.
At 6MB/s a bottleneck occurred somewhere dropping the performance of the
network or storage system below 40MB/s.

I'd say you were doing pretty good.

Jim

-----Original Message-----
From: veritas-bu-bounces at mailman.eng.auburn.edu
[mailto:veritas-bu-bounces at mailman.eng.auburn.edu] On Behalf Of marco
chiapusso
Sent: Tuesday, July 18, 2006 11:46 PM
To: tim.berger at gmail.com; jpiszcz at lucidpixels.com
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: Re: [Veritas-bu] LTO3 Drive Speed Poll


Hi Tim,
what about Number Data Buffer and Size Data Buffer?


>From: "Tim Berger" <tim.berger at gmail.com>
>To: "Justin Piszcz" <jpiszcz at lucidpixels.com>
>CC: veritas-bu at mailman.eng.auburn.edu
>Subject: Re: [Veritas-bu] LTO3 Drive Speed Poll
>Date: Tue, 18 Jul 2006 19:16:25 -0700
>
>On 7/11/06, Justin Piszcz <jpiszcz at lucidpixels.com> wrote:
>>
>>
>>What speeds have other members gotten when doing speed testing to LTO3 
>>drives?
>>
>>Justin.
>
>
>With real-world data, netbackup is reporting from 6MB/sec ( this does 
>not seem right) to about 143.5MB/sec with 2GB fragments over a sample 
>of 1572 fragments for the past 15 days.  Average performance is 
>78.5MB/sec.  These are directly connected IBM LTO3 drives to linux 
>systems using Qlogic 2322's.  Most of our backups fall in the 80 to 
>125MB/sec range.
>
>Creating  /usr/openv/netbackup/NET_BUFFER_SZ with a reasonable value 
>seems to have helped us a lot even though its just going from staging 
>to tape.
>
>--
>-Tim


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