If you check the manual you see the following memory requirements:
The following minimum values for memory:
12 GB.
16 GB if you are using data deduplication.
At least 32 GB
for heavily used servers. Using 32 GB or more of memory enhances
performance of the Tivoli Storage Manager server database inventory.
If you plan to run multiple instances, each instance requires the
memory listed for one server. Multiply the memory for one server by
the number of instances planned for the system.
Node replication processing requires additional memory. Use a minimum
of 32 GB of memory for node replication without data deduplication.
Node replication with data deduplication requires a minimum of 64 GB
of memory.
When you create the active log, you need at least 64 GB of memory to
run replication. If replication and deduplication are both being used,
create an active log of 128 GB in size.