Ubuntu Server 12.04 for low-power home server (NAS mainly). System boots from USB pen-drive (to keep all IDE/SATA ports available for RAID, etc.). System will suspend when idle for time.
pm-suspend is working.
sudo etherwake -D 00:11:22:33:44:55 (from another computer) wakes the server up and it is back on line in less than 15s. So far so good.
The problem is that on resume/wake-up the file system has changed to read-only. From my extensive searching this seems to indicate either (1) that the OS thinks the drive is going bad or (2) the system comes out of sleep before the USB drive is ready and so back to (1).
Can anyone suggest a fix for this?