NFS/SSH/RSYNC issues linked to DNS / DHCP

The NFS & Backuppc server was using DHCP but with a fixed IP configured in the DHCP server (in the router). Sometimes this box was unable to resolve names of other machines on the LAN. I tried fidling with /etc/nsswitch.conf without success. I decided to move from DHCP to fixed IP since the server IP is fixed already anyways; So I also removed NetworkManager* and used /etc/network/interfaces to setup the eth0 interface. I also re-enabled the cronjob to suspend (shut down) the server when idle. Then on the next day I noticed a reboot (clock-driven) and tried to login after a couple minutes but the box wasn't responsive... I connected a screen and keyboard to troubleshoot the issue, just to discover that I forgot to add "auto eth0" in my new /etc/network/interfaces configuration. So after each reboot the server stayed offline :-\ Easy fix, now the hourly suspend/reboot seems to work fine. The script doesn't reboot in case a backup is in progress, or NFS clients are connected. To be verified after some more days.