Limit of SIZE_DATA_BUFFERS on NB 5.1/Win 2003?

[Jim_Bartlett]

I have seen and heard conflicting info, even from Veritas technical support, on changing the value of SIZE_DATA_BUFFERS on the Windows platform. I have a clustered SAN media server on Windows 2003, NB Enterprise 5.1 MP2 and a switched SAN environment with a fibre channel native PV132T with IBM Ultrium LTO2 drives. Unix was easy...set to 16 (NUMBER_DATA_BUFFERS) x 256 and speed was good. On Windows, I have been told to leave at 64K, that there is a max of 128K and that 256K is fine if hardware supports it. Which is true? I am in the middle of a test of 16 x 256 and it is performing better than the tech recommended setting of 128 (num) x 64 (size).

[Yasuhisa_Ishika]

> On Windows, I have been told to leave at 64K, that there is a max of 128K and that 256K is fine if hardware supports it. Which is true?

Yes, it's true. See also http://forums.veritas.com/discussions/thread.jspa?threadID=52265

Be sure to restore as test. Sometimes restore fails although backup ends up successfully.

[Jim_Bartlett]

Which is true? There appears to be no 128KB limit after all. I have had no issues with 256KB.

[Yasuhisa_Ishika]

Both is true. It's depends on hardware and driver.
If you can backup and restore successfuly with 256kB, It's OK on your environment.

[Stumpr2]

Yes the key word is "restore" all too many times I have heard of problems with restoring data. Too many people think of NetBackup as a "backup" solution, but it is useless without restore!