Re: Distinguishing among [unmount, Safely Remove Drive, Eject]
- Date: Sat, 5 May 2018 21:54:53 +0300
- From: Abdullah Ramazanoğlu <ar018@xxxxxxxxx>
- Subject: Re: Distinguishing among [unmount, Safely Remove Drive, Eject]
On Sat, 5 May 2018 11:06:25 -0500 Richard Owlett said:
> What are the distinguishing features of unmount, Safely Remove Drive,
> and Eject?
"Unmount" is the head operation of all, which flushes all pending
(cached/buffered) writes to the media, and detaches it from the filesystem
tree. As for R/O media, it just detaches it from the filesystem. After unmount,
you have a *logically* detached, separate media, standing alone by itself in
your system. It is *physically* attached, though. An unmounted device becomes
inaccesible from filesystem hierarchy (though accessible as a raw partition or
device), immune to power loss, immune to user or system bugs.
"Safely Remove" is a coined term for easily detachable R/W media, meaning
"unmount it, so that it can be manually detached". In some implementations, it
can also attempt to mechanically eject the device if possible (DVD for
"Eject" simply means mechanically eject an ejectable media (DVD). In its
earliest form, it would blindly attempt to eject a mounted CD and fail, because
mount operation locks the mechanism so it cannot be ejected prior to
unmounting. Later versions of "eject" is smart enough to first unmount and then
do its main job (mechanical ejection of media).