Is it advisable to have thousands of files on a single DLM 150 GB tape backstore volume ?
Article ID: 368012
Updated On:
Products
Issue/Introduction
How many files are too 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 150 GB tapes have thousands of files on them now.
Is there a best practice that suggests restore performance could be affected by so many files?
Environment
Vtape
Resolution
There is no limitation on writing files on a tape.
As Vtape uses the high speed access method, when a virtual tape is requested Vtape knows where it is on the tape by using a user catalog field, so it goes directly to this displacement and reads 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 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 these different tape sizes when doing RECYCLE.
Additional Information
As always, please contact Broadcom Support for assistance with Vtape if you have further questions.
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