I have a 720TB storage array and wish to allocate 250TB for use in an MSDP.
I have seen the documentation regarding the 32TB split mount points up to 250TB. However If I already have a 250TB single volume available, Is splitting still required?
I have checked and it has let me create a single 250TB dedup disk pool in Netbackup. If I was to start using this, will I encounter problems once I hit 32TB of used capacity on the 250TB pool?
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
To add to @Nicolai very good points.
If you use a single 250TB volume for MSDP and do run into problems, you may find that support will say you are on your own. Veritas have clearly indicated what is supported - if you go outside this then do so at your own risk.
Secondly which follows on from the above - just because you can do something doesn't mean you should. Stay within the guidelines for the best experience.
Thanks very much for the details
Just to get some clarity regarding the mount points,
The current single volume has 19 x 16TB disk which is 304TB raw and 247TB usable with single RAID6 volume group.
Based on Veritas recommended specs would it be 4 x 16TB disks totalling 64TB raw and 26TB usable in RAID6 for each volume group. A total of 8 volume groups would require 32 x 16TB disks totalling 512TB raw and 208TB usable for the MSDP?
Is the calculation correct or am I missing some here?
The specification for the 250TB pool is based on 8 x 32 TB volumes (which is actually 256TB) for data and 1 1TB volume for the MSDP Catalog.
You calculations on size and disks required look to be correct, but would waste a lot of space.
If it was me (and it is possible with your storage array), I'd create one large RAID6 volume (19 or 20 16TB disks) and then carve this up into the 9 LUNs to then present to the media server. Creating lots of smaller RAID6 volumes would increase the write overhead for each volume compared to a single large RAID6 volume and watse lots of capacity. I'm sure there are storage peoiple out there who may disagree but any decent storage array should have sufficient cache and smarts to make it work.