How many files are to many for a single tape volume?
We are using much less tape now that we are writing to the DLM, but the downside is that these 150GB tapes have thousands of files on them now.
Is there a best practice that suggests restore performance could be affected by so many files?
Looking to make a good overall decision and then not have to worry about changing it later.
There is no limitation on writing files on a tape.
As Ca Vtape uses the high speed access method, when a virtual tape is requested CA Vtape knows where it is on the tape by using a user catalog field, so it goes directly to this displacement and read the data.
The only performance impact is the time to reach this displacement on the tape and read the data. This depends on the tape vendor hardware/software performance (here DLM) not Ca Vtape.
As you have the ability to configure the tape size with the DLM, sending big data files to the DLM tape, so using the large capacity to your advantage, while using less of a DLM tape for smaller data files, is the best practice.
Now you can use different CART3590(n) sizes, and can further adjust based on MAXVOL and PERCENT parameters to manage theses different tape size when doing RECYCLE.
- link to Ca Vtape Documentation: https://support.ca.com/cadocs/0/CA%20Vtape%20Virtual%20Tape%20System%2012%206-z%20OS-ENU/Bookshelf.html
As always, please contact CA Technologies support for CA Vtape if you have further questions.