Running a server completely headless is fine as long as the server boots and remote access is available (via ssh, rdp, vnc or similar). I have a HP mediasmart EX490 server which has no VGA output (though it is possible to get a VGA/PS2 connection with a debug cable). These are some tips for running the EX490 completely headless with Ubuntu.
Modifications to GRUB boot loader default settings in Ubuntu (Tested with Ubuntu 14.04)
Upon an unclean shutdown or due to some other reason the filesystem is not clean, grub will stop before booting the kernel (it’ll wait for keyboard input). Add or uncomment following line in /etc/default/grub. This makes grub continue to boot after prompting for keyboard interaction for 5 seconds.
Ubuntu will also wait for keyboard input (prompting for a confirmation of fsck) if there’re file system inconsistencies detected during boot. Adding or uncommenting following line in /etc/default/rcS.
# automatically repair filesystems with inconsistencies during boot FSCKFIX=yes
After these modifications it is recommended that the grub is updated.
Modifications to /etc/fstab (Tested in Ubuntu 14.04)
for each storage pool drive partition in fstab we can add the options ‘nofail‘ and ‘nobootwait‘ . This setting enables the server to boot even when one or more storage pool disks are removed or dead. For an example here is a fstab entry for a storage pool drive.
UUID=cda16a20-37aa-11e6-ac61-9e71128cae77 /mnt/hdd4 ext4 defaults,noatime,data=writeback,nofail,nobootwait 0 2
Note: The ‘nobootwait’ option is no longer available for Ubuntu 16.04 it seems.
With these options I have managed to run Ubuntu with Greyhole as a home server completely headless.