/var permissions are either a red herring or incidental. For the uid-to-name lookup to work, the following must be correct, in order:
/etc/nsswitch.conf needs to have permissions 0644, owner root:root.
passwd entry in that file needs to be correct - given the very large IDs, you're probably not using just the local password file, but some ldap or AD setup? Make sure that it's listed, and listed early on.
- The service that actually provides your identities needs to be up and running and accepting your queries - for local users, that means that
/etc/passwd must have permissions 0644 and owner root:root.
- The client library for your identity service may have permissions requirements for its config, cache, or both. This is where the
/var permissions would come in, but without knowing more about what you use for authentication, that's not possible to troubleshoot. At a minimum, make sure that
/var itself has permissions 0755, owner root:root; directories it contains should be owned by either an obvious system user/group (e.g. "mail" for
/var/mail) or root, and not be world-writable (with the exception of
/var/tmp, if it exists, which should be root-owned and have permissions 1777).
If that doesn't help (and even if it does), please provide more information about your auth system - LDAP, samba, AD (via what?), or something else.