HP LTO-4 drive - largest selectable buffer size is 64k

[chrisit]

Our LTO-4 drive's performance is very low (about 2000 MB/min). Even though that we do have a brand new ML350p G8 with 32GB RAM and a RAID10 array consisting of 4 SSDs!

As far as I found out we need to increase the buffer size in BE's settings for the HP LTO-4 drive. But the largest available buffer size in the dropdown is just 64k!

Any hints?

Thank you!
Chris

[CraigV]

THat's it...that's the highest you can go for that particular drive then.

Look at pkh's article on tuning your drive and see if this is of benefit:

https://www.veritas.com/community/articles/tuning-my-lto4-tape-drive

Also make sure you're using the Symantec drivers for the tape drive...use tapeinst.exe to install them.

Thanks!

[pkh]

1) If you are running any HP Insight software, uninstall them.

2) If you are using a tape library make sure it appears in the Windows Device Manager as an Unknown Medium Changer with a Microsoft driver.

3) Your tape drive should be using a Symantec driver.

If you are doing the above and you still cannot get other buffer settings, re-install the tape library and tape drive

1) Go to the Storage tab and delete the tape drive and tape library

2) Stop the media server and the library

3) Start the tape library

4) Start the media server

5) Ensure that the library and tape drive is recognised and functioning correctly in the Windows Device Manager. The library should appear as an Unknown Medium Changer with a Microsoft driver and the tape drive should have a Symantec driver.

If the problem persists, then log a support so that the support engineer can help you.

[chrisit]

Thank you for your replies!

I did read the tuning article, but am afraid to do the registry entries as I'm not sure how to address the drive (and not my SSDs) properly.

I installed the Symantec driver (was using the MS driver before), but this didn't change the situation.

Reinstalling the tape drive did not work, as the context menu entry to delete the drive is always greyed out - even when I disable/stop the drive.

[CraigV]

Have you tried to update the firmware on the drive through HP LTT?

Thanks!

[pkh]

Go to the BE installation directory and use tapeinst.exe to delete any instance of the tape drive

[Biker_Dude]

The HBA can also limit the block and buffer sizes. If the tape drive is connected to the RAID controller, check if it actually supports tape. If it does not, then it's advised to move it to one that does in an attempt to increase performance (no guarantees though.)

In addition to updating the firmware, keeping the tape head clean is imperative. Dirty/clogged heads will cause the drive to under-perform before eventually tossing read/write errors. Grab a known good cleaning tape or a new one and pop it in to the drive. It will auto-eject when the cleaning (if applicable) is done.

Also, is the low performance tied to a handful of media, all media, one media, etc...?

Although we do not certify HBAs (Host Bus Adapters), below is a TechNote of known good controllers which support tape:

https://www.veritas.com/support/en_US/article.TECH70907

Hope this helps you.