I would like to reduce the memory usage on the clients, since they're
continuously producing data and it slows them down.
How do you know this? Most of the client memory is in page cache, which is entirely normal and even improving the buffering on the server wont prevent aggressive caching of this data client side.
Have you tried flushing the page cache (...
The simplest way is to run tshark on the client with options to print rpc response times:
$ tshark -i any -f "port 2049" -Y rpc -Tfields \
-E separator=/t -E header=y \
-e frame.number \
-e rpc.repframe \
-e ip.src -e ip.dst \
The output will be something like:
frame.number rpc.repframe rpc.time ip....
No, forcing use of less memory is likely to make things slower, not faster. You are spending power on 188 GB of fast DRAM already, might as well use it.
Client host has 188 GB MemTotal, and is using 162 GB of it for Cached. Actually quite low on the memory demands, note 123 GB MemAvailable that can be freed very quickly. Most of the 40 GB of Shmem is ...
The solution in my case was the following:
I tried making LDAP DB on my production DC look like LDAP DB on the fresh DC (which is working). So I changed some fields. Rebooted everything. And it worked!
What I changed exactly.
I added/changed the following fields in the object dn: DC=my,DC=domain using ldbedit -H /var/lib/samba/private/sam.ldb: