Being careful not to shoot yourself in the foot when cleaning up users and home directories on AIX and Linux
brian_s 270002K5X3 Comment (1) Visits (4516)
It is possible on Linux or AIX to have users that share a home directory. For example, you might have user1, user2, and user3 all have their home directories set to /sharedhome.
Anytime you are deleting users and home directories you need to keep this in mind. You might only need to delete "user1" but want to leave "user2" and "user3" unaffected. But if you delete user1 and its home directory you might end up deleting the shared home directory which would have a big impact on "user2" and "user3".
Let's look at this situation:
AIX and Red Hat both have a "userdel" command that will optionally erase the users home directory as well ("-r" flag).
On most versions of AIX, if you did a "userdel -r" on any one of the 3 users, it would deleted the /sharedhome directory which would impact the remaining 2 users that you didn't want to affect.
On Red Hat Linux, "userdel" tries to be smarter, and verifies that the owner of the home directory matches the user that is being deleted. Thus, if you did a "userdel -r user1" it would happily wipe out /sharedhome, but if you did a "userdel -r user2" or "userdel -r user3" it wouldn't delete /sharedhome because the owner of the directory doesn't match the user being deleted.
Here is a one-liner that will do a better job checking to see if a given directory is a shared home directory between multiple users:
Change "/sharedhome" to whatever directory you would like to check. If this comes back and says it is a shared home directory, then you need to do more research before attempting to delete the home directory.
So anytime you are cleaning up users and home directories, always keep in mind that users might have shared home directories and that under some circumstances AIX and Linux will wipe out these shared home directories which might affect other users on the system.