I have many Data Domain, some DD2200 and other model DD2500, all have a high consumption of RAM, but my backups work very well.
Depending on the configuration of Data Domain disks, the system contains a certain value of RAM, look at the image:
The foundation for Data Domain’s industry leading performance is the Stream-Informed Segment Layout (SISL) scaling architecture. SISL enables Data Domain systems to perform 99% of the deduplication processing in CPU and RAM, which gives it fantastic performance even with inefficient protocols like CIFS and NFS. SISL means Data Domain systems do not rely on increasing the number of disks to increase performance and therefore are not spindle-bound like other deduplication platforms. This is why Data Domain systems have dramatic increases in performance with each successive generation of Intel processors – every time Intel processors get faster, Data Domain systems get faster.
So the server uses a lot of RAM and can use it at any time, but this is to make the backups faster. On servers with low memory the system consumes almost 100%.
Data Domain uses a lot of RAM and can use it at any time, but this is to make the backups faster. On DD with low memory the system consumes almost 100%.
In short, I suggest you look for another reason to justify the slow performance of your backups.
My Data Domain systems:
DD2200 - 1 (16 GB):
DD2200 - 2 (8 GB):
DD2200 - 3 ( 8 GB):