I'm curious:

1) Where may I get a copy of this paper?

2) Does the paper list exactly how they went about performing their test?

Right now I'm tuning a DR environment. I mail tapes to my off site 
facility, phase 1 and phase 2 import my images in and then restore. 
Other than that, my Master, Media, clients and libraries just sit there. 
So I've eliminated the factors of "Is there other stuff running that 
could impact performance".

Furhtermore, according to page 106 of the Netbackup Performance and 
Tuning Guide:

"IMPORTANT: Because the data buffer size equals the tape I/O size, the value
specified in SIZE_DATA_BUFFERS must not exceed the maximum tape I/O size
supported by the tape drive or operating system. "

Where do I go to find the tape I/O size? And where do I find the tape 
I/O size supported by the tape drive and OS? My configuration is:

Tape Drives: LTO-4 IBM
# or drives: 6
Master Server OS: RHEL
SAN Media Server: Tru64
Library Vendor and Model: Spectra Logic T380

Would Red Hat, IBM, Spectra Logic or the LTO site have the supported 
tape I/O size numbers?

Thanks.

- Heathe Kyle Yeakley

> There was a paper written by IBM or Symantec awhile ago when they did 
> testing, the most optimal was 262144 (256k) for the size and 32 for 
> the number, beyond that (note: this paper is OLD, LTO-2)-- increasing 
> the number did not buy any improvement in performance.
>
> Don't forget about SIZE_DATA_BUFFER_DISK and _RESTORE to that
>                    NUMBER_DATA_BUFFERS_RESTORE
>
> Also NET_BUFFER_SZ (from clients)-- currently using 1MB here.
>
> Justin.
>

_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu