Netbackup tuning guide, the size of shares data buffers UNIX
According the the Netbackup tuning guide, the size of shares data buffers UNIX should follow the following guideline:
64K for tapes
256K for disk
In a case where we have a VTL. I assume that the virtual tapes are considered as normal tapes for netbackup. So SIZE_DATA_BUFFERS is the value taken for the virtual tapes instead of SIZE_DATA_BUFFERS_DISK. But should virtual tapes not be treated as disks?
And if I consider to treat it as disk, the value I have to put would need to be 256K in the SIZE_DATA_BUFFERS. And then what if I need to set the value for real physical tapes?
Thank you in advance for considering my question.
I'm using 256K for all modern tape devices including VTL. You can use bigger size than 256K for disk buffers.
But every installation is different, so you must perform backup and restore tests to find the best value for all buffers. Do not forget to test network buffers sizes.
check this pdf
http://www.symantec.com/connect/sites/default/files/IA%20B47.pdf