Hi, We have lots of Linux storage servers running combinations of RHEL7, RHEL8 and more recently RHEL9. We also use "manage-gids" and have lots of groups of users and apply permissions to directories on the exported filesystems. We also use sssd and AD/LDAP on these storage servers to resolve the groups and do the user lookups. This setup has worked great for our needs for many years but we have noticed a change in RHEL9 which results in many more uid/gid lookups hitting our LDAP servers. It seems like with RHEL7 & 8 era kernels and nfs-utils, sssd/nss would receive a single request from rpc.mountd whereas with RHEL9 we now get duplicated requests for each rpc.mountd thread (8 by default) even for a single client mount. So 8 uid/gid requests hit sssd at the same time, and because it's not in cache, all those 8 requests go out over the wire to our AD server. So for lookups not in the cache, we have 8 times more requests hitting our LDAP servers. Not to mention that sssd sometimes crashes or loses connectivity with the LDAP server with this increased load. I had a look through the changes for linux-nfs but nothing jumped out at me in that time frame (other than code to make exportd multi-threaded). Does anyone have any ideas where this change of behaviour might be coming from? RHEL9: nfs-utils-2.5.4 RHEL8: nfs-utils-2.3.3 Cheers, Daire
