Hi mop1987
While a single drive configuration is technical possible, it's not what Veritas recommend.
Veritas recommendation is based on in-house testing plus feedback from customers. As customer we are not always explained why a certain configuration is recommended.
But if you have a look at : https://www.veritas.com/content/support/en_US/article.100038442
the note says:
Note: Veritas has defined the Maximum MSDP storage capacity. The information is referenced in the About MSDP storage capacity section of the NetBackup Deduplication Guide for Version 8.2. Failure to adhere to these settings could result in performance related issues due to data not being balanced optimally across all volumes.
Meaning, a single configuration may work but could impact performance. Performance issues are difficult to solve, and Veritas is likely not able to help unless you are following their recommendation.
My recommendation: Use time now to get the configuration right, when disk is empty, than fix it when you have 250 TiB data on disk.
Hope you can use the info
Best Regards
Nicolai