I’m a little confused about multiple partitions and or DDBs limitation. There are several places when limits are mentioned like the one and only Hardware Specifications for Deduplication Mode
which mentions “2 DDB Disks” per MA

and
Configuring Additional Partitions for a Deduplication Database
which mentions “30 DDB partitions” per MA.
Also, In my recent discussion with PS member I was told that a partition should be treated as DDB itself.
All of this creates a lot of confusion like
a) is “DDB Disk” the same as DDB?
b) is “DDB partition” the same as DDB?
If you look at 1) /Scaling and Resiliency there is a information
The back-end size of the data. For example: Each 2 TiB DDB disk holds up to 250 TiB for disk and 500 TiB for cloud extra large MediaAgent.
That means that a DDB with only 1 partition needs a 2TiB DDB disk for 250TiB backups (backend) and we know from link 1) that we can have maximum of a 2 DDB disks per MA. So the confusion continues
c) does that mean that if I want to store 500TB BET on 1 MediaAgent I need to create 2 separate DDBs aka Storage Pools or can I create 1 DDB aka Storage Pool with 2 partitions hosted on the same MA?
d) taking this even further is it supported configuration to have 4-partitioned DDB aka Storage Pool on 1 MA?
If you add up that 1 MA can have a maximum of 2 DDB Disks and (assuming that a DDB disk is the same as DDB) 1 DDB aka Storage Pool can have a maximum of 4 partitions that gives a theoretical maximum of 8 partitions per MA
e) is having 8 partitions on 1 MA a supported configuration?
And finally on modern server you can have 128 physical cores, TBs of RAM and as many as 24 NVMe drives
f) so why there is a 2 DDB disks limitation per MA?
I am really curious about all that and would really like to understand that better.
Cheers,
Best answer by Prasad Nara
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