What values ​​should I change in autoloader LTO5 in Backup exec if I change the block size to 512 KB?

[Paulo_Mendez]

What values ​​should I change in autoloader LTO5 in Backup exec if I change the block size to 512 KB?


What additional parameters should I change?

[Ken_Putnam]

The onlyone you really need to worry about would be the Buffer Size and number of buffers

Remember that all your buffers will be in memory, so ensure that your media server has plenty of RAM

You could start with a Buffer size of 1024 KB (1 MB) and 10 buffers.

Whatever you try, be sure to do a test backup and restore before you first production backup with the changed settings

[pkh]

I would suggest that you take baby steps and slowly increase your block size and bugger size.  Tuning a tape drive is not an instant affair where you select a certain block size or buffer size and that's it.  Choosing 512kb as a block size may not necessarily mean that you would get the best performance out of your tape drive.  You got to try various block and buffer sizes and see which is the best for your environment.  It is a long drawn out affair.  It is a case of change block/buffer size, observe the result and change again if necessary.  It took me 6 months to tune my tape drive to its optimal settings.  See my article below

https://www-secure.symantec.com/connect/articles/tuning-my-lto4-tape-drive

Although it is written for LTO4, the methodology is applicable to all tape drives.

[teiva-boy]

pkh is right, each drive vendor implements different firmwares and buffers within the drive itself.  SO your mileage will vary.  Testing is the only thing you can do.

As always, test your restores too!  Not just with new settings, but old tapes too with the old settings.  You may achieve faster backups, but can't read reliably old backup sets.