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optimal Buffer Size/Number settings for VTL in NBU 7.1

Created: 26 Oct 2012 • Updated: 19 Dec 2012 | 4 comments
This issue has been solved. See solution.

Is there a recommended Buffer Size/Number settings for VTL for NBU Server v7.1 for SuSE?

(For instance, for OST its is 256K/64)


Edwin Danso

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mph999's picture

It depends - there are tuning settings and so what works for one environment, may not work for another.

However, a size setting of 262144 is a good starting point.

Regarding number, try 128, run test, note the speed then try 256 and see if it improves.


Regards,  Martin
Setting Logs in NetBackup:
Edwin Danso's picture

(the environment is EMC Data Domain DD670, Data Domain OS

Marianne's picture

Ask your EMC reseller for their Best Practice docs.
I remember some years ago at a customer where EMC EDLs were used as VTL, the EMC guys gave us a doc with NBU tuning recommendations.
Please bear in mind that buffer settings for VTL will also be used for physical tape drives.

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links

Yasuhisa Ishikawa's picture

I prefer to use default buffer size because higher value sometime lead to I/O failure(depending on hardware).

Today I have tested on Oracle M3000 server with HP Ultrium 5 drive. I got 150MB/s with default buffer size and 64 buffers, and 330MB/s with 128 buffers.

Authorized Symantec Consultant(ASC) Data Protection in Tokyo, Japan