598. Move /var, /tmp, /opt to separate partitions

1. First create the partitions on a disk. In my case I created partitions on a different disk from the root partition.

2. Figure out the uuids:

ls /dev/disk/by-uuid -lah

lrwxrwxrwx 1 root root  10 Oct 22 14:02 28b59809-7dfb-4ce4-a4da-6f118171ea07 -> ../../sdb2
lrwxrwxrwx 1 root root   9 Oct 22 14:45 52f07f83-3a72-457c-b25f-7aa4f3e76461 -> ../../sdc
lrwxrwxrwx 1 root root  10 Oct  7 14:42 8a5ca4ae-9963-47ea-99c3-2335c7dc8118 -> ../../sda6
lrwxrwxrwx 1 root root  10 Oct  7 14:42 9243ff6b-9834-4fa3-a93f-10a350f85687 -> ../../sda1
lrwxrwxrwx 1 root root  10 Oct 22 14:02 9f785dde-1d3a-4063-90e7-054f3d031e05 -> ../../sdb3
lrwxrwxrwx 1 root root  10 Oct 22 14:02 eacf2cad-d462-45b2-afeb-2c5ddf5669b8 -> ../../sdb4
lrwxrwxrwx 1 root root  10 Oct  7 14:42 f25a484c-e8e2-4ead-808b-96dd5e915020 -> ../../sda5
lrwxrwxrwx 1 root root  10 Oct 22 14:02 f4280c34-04d6-4def-963a-507e68dd483d -> ../../sdb1

I know that I'm looking for sbd2 (label: tmp), sdb3 (label: opt) and sdb4 (label: var). We'll use these uuids later for our /etc/fstab

3. Move /opt, as it's the easiest (should be reasonably static).

sudo udisks --mount /dev/sdb3

Mounted /org/freedesktop/UDisks/devices/sdb3 at /media/opt

sudo cp -ax /opt/* /media/opt

Edit /etc/fstab:

 

UUID=9f785dde-1d3a-4063-90e7-054f3d031e05 /opt            ext4    defaults,user_xattr  0  2

Move the old /opt and mount the new one:

sudo mv /opt /opt.old
sudo mount /opt

And you should be good to go. Check with df -h:

[..]
/dev/sdb3                                                72G   28G   41G  41% /opt

4. Move /var and /tmp

You can use init 1 according to http://unix.stackexchange.com/questions/131311/moving-var-home-to-separate-partition. Note that doing so will kill your graphical session and stop or restart most of the services i.e. close open documents before your continue. You'll then get dumped into a vty.

Open a terminal and type

init 1

which dumps you into a root terminal. Then, as root, do

mkdir /media/var
mount /dev/sdb4 /media/var
cp -ax /var/* /media/var
mkdir /media/tmp
mount /dev/sdb2 /media/tmp
cp -ax /tmp/* /media/tmp
mv /tmp /tmp.old
mv /var /var.old
mkdir /tmp
chmod 777 /tmp
mkdir /var
umount /media/var
umount /media/tmp

Changing the permissions for /tmp is important -- if they aren't generous enough it can cause all sorts of issues. In my case it was manifested by me being unable to log onto a GUI (e.g. gnome) from GDM3 -- I would get booted back to the login screen.

Edit /etc/fstab and add:

UUID=28b59809-7dfb-4ce4-a4da-6f118171ea07 /tmp            ext4    defaults,user_xattr  0  2
UUID=eacf2cad-d462-45b2-afeb-2c5ddf5669b8 /var            ext4    defaults,user_xattr  0  2 

Note: I don't know what the best values for the attributes are. I just took what I used for /home, which is probably not optimal. You may want to do your own research into this. Then do

mount /tmp
mount /var
init 2

Once you've established that all is well you can delete /var.old and /tmp.old.
df -h shows

Filesystem                                              Size  Used Avail Use% Mounted on
rootfs                                                   92G   32G   56G  37% /
udev                                                     10M     0   10M   0% /dev
tmpfs                                                   798M  1.1M  797M   1% /run
/dev/disk/by-uuid/9243ff6b-9834-4fa3-a93f-10a350f85687   92G   32G   56G  37% /
tmpfs                                                   5.0M     0  5.0M   0% /run/lock
tmpfs                                                   4.6G   88K  4.6G   1% /run/shm
/dev/sda6                                               734G  555G  142G  80% /home
/dev/sdb3                                                72G   28G   41G  41% /opt
/dev/sdb2                                                72G   53M   69G   1% /tmp
/dev/sdb4                                                48G  8.8G   37G  20% /var

597. Missing partition -- gparted shows unallocated space

The issue:
I'm low on space on my / partition since ECCE has a way of putting really large files in /tmp. Rather than trying to fix the behaviour of ECCE, I'm planning on moving /tmp to a separate disk that's dedicated to highio processes and where ECCE can't cause my / to fill up. I might move /opt as well, to free even more space. The first step in such a move is to create an additional partition on your target disk and for that gparted is good as it can move all the data before creating the new partition.

Imagine my surprise when I fired up gparted and saw:

Using Disk Utilities (palimpsest) it doesn't look too odd:

Using fdisk I see a complete lack of partitions:

sudo fdisk /dev/sdb

Command (m for help): p
Disk /dev/sdb: 1000 GB, 1000202273280 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System 
Command (m for help):                   

---

This may be a job for testdisk. I fired it up with sudo, selected Intel type partition, and kept selecting the defaults -- eventually my partition showed up. I then did a deep search to make sure everything was ok.

I then check using palimpsest and gparted:

(I also screwed up, then fixed a disk with a different issue -- but because I'm not really sure what I did to fix it I'll make a separate post about that at a later date. Maybe.)

596. Debian Jessie -- shutdown takes 'forever' (five minutes according to stopwatch!)

I've been annoyed for a couple of months now that shutting down my laptop, which has an SSD, takes up to five minutes. If I wanted that kind of shutdown times I could run Windows Vista...

Either way, it turns out that it's affecting certain systems with samba:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=762002

The issue is illustrated below, which showed that it took five minutes to shut down samba -- and that's what's preventing the system from shutting down:

sudo service samba stop
ps aux|grep sam && date

root      2765  0.0  0.0  65468  2100 pts/0    S+   10:45   0:00 sudo service samba stop
root      2766  0.0  0.0  26252  1172 pts/0    S+   10:45   0:00 systemctl stop samba.service
root      2785  0.0  0.0   4308   636 ?        Ss   10:45   0:00 /bin/sh /etc/init.d/samba stop
Sunday 12 October  10:49:28 AEDT 2014

The solution is pretty simple though -- remove a set of symlinks:

First establish that they are present:

me@oxygen:/etc$ find rc* -name "*samba*"|xargs -I {} ls {} -lah
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc0.d/K01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc0.d/K01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc1.d/K01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc1.d/K01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc2.d/S01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc2.d/S01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc3.d/S01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc3.d/S01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc4.d/S01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc4.d/S01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc5.d/S01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc5.d/S01samba-ad-dc -> ../init.d/samba-ad-dc
lrwxrwxrwx 1 root root 15 Sep 16  2013 rc6.d/K01samba -> ../init.d/samba
lrwxrwxrwx 1 root root 21 Sep 15 10:46 rc6.d/K01samba-ad-dc -> ../init.d/samba-ad-dc

Then remove them:

me@oxygen:/etc$ sudo update-rc.d samba remove 
me@oxygen:/etc$ sudo update-rc.d smbd remove 

Done!