Fine Tune LTO 5 Tape Drive
Hi
I'm looking for some advice/guidance on getting the best performance out of my LTO 5 tape drive.
This is my setup:
HP 1/8 G2 LTO 5 AutoLoader - connected to...
HP DL360 G6 Server - via...
P212/256mb Smart Array Controller.
Then...
HP MSA2012i SAN - connected to...
another HP DL360 G6 - via...
HP 1800 8g switch.
There is also a HP 5308xl switch (with 1gb GBICs) connecting the two servers.
I have data stored on the SAN which I want to backup using the 1/8 G2 Autoloader, so the network/data route of this is...
MSA2012i -- HP 1800 8g -- DL360 -- 5308xl -- DL360 -- 1/8 Autoloader.
All network connections are 1gb.
I have Backup Exec 2010 G3. The default configuration for the LTO5 drive is used (64kb block size, 64kb buffer, 10 buffers, 0 high water). I also have 'Unknown Media Changer' set as Autoloader driver, and the latest Semantic DDI drivers for the tape driver.
As a test, to backup 18.3gb (34783) files of data, the data rate I get is 2,851mb/min.
I have done some tests increasing the block size and buffer count, but the best rate I can get is 2,890mb/min when I set block size and buffer count to 256kb. But is must be able to go faster than this...shouldn't it??
Any thoughts on this would be much appreciated.
Thanks
Andrew
Hi,
I think that there may be some caching between the data store / reading and the writing.
The caching will get a speed boost early on until the cache fills up, the estimation of how fast the copy is happening will seem very fast as it is writing to cache / memory and not disk, once the cache / memory has been used up the speed may then drop like a stone and the estimation has to drop very quickly and will keep dropping as it cannot achieve that cache rate again.
It will eventually get down around the non-cache rate.
Regards,
Andrew
Nebula Computer Services