Very high non-cache kernel dynamic

Hello everyone,

I hope I'm posting in the right place.

I'm a sysadmin of a cluster and these last days we noticed a high memory usage has started to take down our main login machine. After investigating, we found that the Noncache kernel dynamic memory is unusually large, and this seems to be at the root of the problem.

I managed to free up some space by doing, but the 38.9G of Noncache memory doesn't move very much.

sync 
echo 3 > /proc/sys/vm/drop_caches

https://preview.redd.it/dup3a1b334sd1.png?width=1033&format=png&auto=webp&s=4585351e917cbed8c83b7d959bf86bdd9103cc64

Additionally, I suspect that this memory appeared after data transfer to another backup server using scp. However, I haven't been able to find the exact cause of this problem.

Has anyone experienced something similar or could suggest ways to dig deeper into this issue?

Thanks in advance for your help!