LinuxQuestions.org - Lost write privledges on 2 drives and cant unmount portable drive

Quote:

Originally Posted by 3lud13 (Post 4794950)

Somehow last night while i was trying to get my windows partition to automount on startup last night i have gained the same with my portable hard drive
Currently cant unmount my portable hard drive and have no write privlidges the same for my windows partition it seems not sure what i did but would be great to be able to get write privlidges back on both partitions and be able to unmount my portable drive.
My guess is to fix the unmount problem the mount point at
/media/3ludz Portable Terabyte
needs to be deleted but I tried that and it cant be deleted TBH not even sure how it got there as I didnt even create it.
To get write privlidges back I thought maybe I could right click go properties and change it from there but it comes up
"The permissions could not be determined" on both drives
my other option is its something that needs to be removed in my fstab but I have no idea about changing that so have enclosed an image of it.
Hopefully someonecan help me out.

Check your write privileges with ls -l in a terminal. cd /file/path/of/interest first, e.g.

Code:

~/Documents $ cd ~

~ $ ls -l

total 1204

-rw-r--r--  1 g    users      0 Oct  1 08:09 2

drwxrwxrwx  4 g    users  4096 Sep 29 19:19 Calibre Library/

drwxrwxrwx  2 g    users  4096 Oct  2 20:07 DeletedMusic/

drwxrwxrwx  2 g    users  4096 Sep 29 19:19 Desktop/

drwxrwxrwx  7 g    users  4096 Oct  2 20:07 Documents/

drwxrwxrwx  5 g    users  4096 Sep 30 17:18 Downloads/

drwxrwxrwx  3 g    users  4096 Sep 30 11:42 Films/

drwxr-xr-x 18 root root    4096 Sep 14 09:03 Installed/

The first column shows the permissions, the 2nd thru 4th characters pertain to the owner of the directory or file concerned. The 3rd column shows who is the owner and the 4th the group the owner belongs to. So presumably these would be your user name and the group you belong to. If they are not correct you would need to correct them using 'chown'. If the owner is shown as a member of the 'root' group, you would need to log in as root in order to make such change.

Permissions can be set with 'chmod', e.g. 'chmod -R 777' gives everyone read, write and execute privileges in every file in the current directory and all its sub-directories.

The command 'mount' will show you if and how the problem drive is currently mounted. If it is mounted you use the command 'umount /mount/point' to unmount it. Note the command is NOT 'unmount'.

Log in as root to use mount or umount. In your terminal 'su -lm' will keep you at the same directory it currently shows, and then enter the root password. See man pages for these commands for full details.

Actually the situation with permissions is more complex than I have described it above, and I strongly recommend that you study these tutorials for permissions
http://www.dartmouth.edu/~rc/help/faq/permissions.html
http://www.grymoire.com/Unix/Permissions.html

To summarize your situation here:
To change the permissions of a file you must be logged in as the owner and in the same group as that shown by ls -l for the file concerned. IOW, for the example permissions shown above, only user 'g' logged in as a member of the group 'users' can change the permissions for files and directories shown as belonging to 'g users'. If you happened to log in as 'g someothergroup' you can't change them.
To read or write to a file, not only must you have read or write permission for that file, but the same permission for every directory above that file up to and including the parent directory.
Windows nfs file system is more stringently handled. Such files are always owned by 'Root Root', and you must log in as such in order to change the permissions of such files.
To read or write to an nfs file you need the same permissions chain for the file up to the parent directory as you do for unix files.

I remember permissions virtually drove me insane while I was learning them, so, good luck!