Comment 3 for bug 521672

Is this behavior really by design? If so, it is a very bad one. By default, the system should wait until all file systems are available before letting the user log in. Otherwise, the user can suffer data loss as follows:

1) Boot with unmounted file systems. The mount points will look like empty directories.
2) The user logs in.
3) Program X starts up and finds that expected data Y is missing.
4) Program X proceeds to perform cleanup or initialization based on data Y having disappeared.

Data loss has now already occurred in the case when program X writes to a different file system than where Y is located. For instance, if the home directory was mounted, but not the file system that contains my digital photos, a photo manager will now clear out metadata about the supposedly deleted pictures from its database. Some programs will ask the user first about this, but as is well known the user always answers "yes".

Otherwise:

5) The missing file system is mounted.
6) Program X keeps writing a clean slate of data in the location of Y, oblivious to the fact that it is now overwriting the real data, which has suddenly reappeared.