Ubuntu – Share Ext4 Partition Over Network

It could be that some process still has deleted files open. If this is the case then they will not appear in the du output but would still be counted in the df output.

One quick way to check for these is to list /proc as user root (hint sudo su should get you a root shell). Any open, but deleted files will have (deleted) at the end of the symbolic link target name.

ls -l /proc/*/fd/* | grep deleted | grep /home

should give you a list of any files open. Once you have that then an ls -lL of the specific file should give you the size of the file.

As an example (using /tmp on my system because there are no examples on /home here) I see a few files owned by user mysql.

richm@viking:/$ sudo su
root@viking:/# ls -l /proc/*/fd/* | grep deleted | grep /tmp
lrwx------ 1 root     root     64 Oct 13 06:30 /proc/1489/fd/11 -> /tmp/ibwmCqpg (deleted)
lrwx------ 1 root     root     64 Oct 13 06:30 /proc/1491/fd/12 -> /tmp/ib9MTMQi (deleted)
root@viking:/# ls -lL /proc/1489/fd/11
-rw------- 0 mysql2 mysql2 0 Aug 24 14:09 /proc/1489/fd/11
root@viking:/# ls -lL /proc/1491/fd/12
-rw------- 0 mysql mysql 1320 Oct 15 13:40 /proc/1491/fd/12

If you have any processes with large deleted files open then stoping the process should be enough to reclaim the disk space. Alternatively a reboot should do the same thing.

After a bit of searching, I found the solution myself:

First, I had to give myself the ownership over /dev/sda4, and I had to give group and others read and execute permission. I did that by changing the partition entry in /etc/fstab.

To do that, I had to know my uid and gid. So the first thing I did was writing the following command in a Terminal:

id $USER

This will give an output like this:

UID=1000(myname) GID=1000(myname) groups=1000(myname),4(adm),24(cdrom), ...

So now I knew that both my uid and my gid were 1000.

Do you already know the name of the NTFS partition? If not, type this command in a Terminal:

sudo blkid

and write down the NTFS partition on a piece of paper.

Now, to change the permissions, I edited /etc/fstab with the nano text editor. So, the next command you have to type in a terminal is:

sudo nano /etc/fstab

Go all the way down and type this line:

/dev/sda4 /media/Data ntfs defaults,umask=0022,uid=YourUIDHere,gid=YourGIDHere 0 0

(You should replace /dev/sda4 by the NTFS partition that you wrote down earlier).

_{Explanation: umask=0022 sets the directory's (d) permissions permissions to drwxr-xr-x, to make sure that the user (me) can read, write and execute (rwx) while the group and others can only read and execute (r-x) the directory, which is what I wanted.}

After that, I could mark the three checkboxes without any errors, and the folder would be shared over the network. Because I was not sure whether the sharing settings would be kept after a restart, I unchecked the checkboxes and added some lines in /etc/samba/smb.conf instead. I did that this way:

In a terminal, I typed sudo nano /etc/samba/smb.conf

I scrolled down to the last line, and pasted the following there:

[MyShare]
    comment = My Share
    path = /media/Data/FolderToBeShared
    browseable = yes
    guest ok = yes
    read only = yes
    create mask = 0755

I saved the file, and then rebooted. The folder was accessible from the network now.