[chousuke]

Linux has support for multipath devices, so disks disappearing and re-appearing at runtime definitely isn't a new concept. Making it work with a single disk might take some work though.

If the power cycle is controlled, then the kernel can be reasonably sure that the re-appearing device is the same one. File handles wouldn't really be affected as long as the mounted filesystem can resume IO after the device reappears.

Most likely you'd still want to use a RAID scheme and/or data checksumming as an extra layer to ensure data integrity though.