Peter's Blog

I was missing Midnight Commander in my debian server setup. Using dselect to try to install it and searching for 'midnight' or 'commander' did not find it. Woe. Tried downloading the source but running ./configure complained about missing glibc. Googling revealed some religious wars about gnome bloat and glibc dependancies.

Out of desperation went back to dselect and searched for 'mc'. This matched umpteen things but eventually I found midnight commander! Installed instantly! The description clearly called it 'midnight commander', no weird spellings, k's in odd places, l33t speak etc.

Searches for 'midnight' and 'commander' still fail, even after installing it, so what does the search option in dselect search through? There are 17,000 packages to choose from, a decent search facility is pretty much essential.

For a while now I have had many dependancy errors when trying to install packages on my ubuntu server at work. These all boiled down to the postfix package failing to configure. I decided to look into it.

Explicitly trying to configure the postfix package didn't work:

   1  pcw@rd-pcw2:~ $ sudo dpkg --configure postfix
   2  Password:
   3  Setting up postfix (2.1.5-9ubuntu3) ...
   4  
   5  Postfix configuration was untouched.  If you need to make changes, edit
   6  /etc/postfix/main.cf (and others) as needed.  To view Postfix configuration
   7  values, see postconf(1).
   8  
   9  After modifying main.cf, be sure to run '/etc/init.d/postfix reload'.
  10  
  11  Running newaliases
  12   * Starting Postfix Mail Transport Agent...
  13   *stfix/postfix-script: fatal: the Postfix mail system is already running[fail]
  14  invoke-rc.d: initscript postfix, action "start" failed.
  15  dpkg: error processing postfix (--configure):
  16   subprocess post-installation script returned error exit status 1
  17  Errors were encountered while processing:
  18   postfix

The problem looks like it tried to start the postfix server but it was already running. Stupid thing. I stopped the postfix server explicitly:

sudo /etc/init.d/postfix stop

and tried again and this time it was successful.

Back into dselect, configure all pending packages and everything is happy.

dselect is a package management system for debian based linux systems. It presents a very long list of applications for you to pick and install on your linux box.

Was using dselect under Ubuntu linux to install some stuff over an ssh connection. While the install was underway the network connection died. When the network came up again I could not continue using dselect without getting the following error:

dselect: the access method area is already locked

After much fiddling, I found the lock file and deleting it fixed the problem:

sudo rm /var/lib/dpkg/methlock

While I was messing around I found out how to disable the annoying help messages that dselect keeps popping up. Just edit the file /etc/dpkg/dselect.cfg and add the line:

expert

UPDATE: this post which describes a more modern approach using xming which is a far better X server than cygwin.

Retracing earlier steps I find Ubunto works as a headless X box, running programs while displaying remotely on a windows 2000 pc (X windows has the definitions of 'client' and 'server' randomised).

Here are the steps it takes to do this, rationalised from what I wrote before:

• Install Cygwin on the windows box. In particular, install the openssh and X11 base packages.
• Edit the sshd_config file on the remote server and make sure this is set:

  X11Forwarding yes
  

  and restart sshd. On my Ubuntu this was how it was already set up.
• on the local pc run the cygwin command startxwin.bat. It is buried in:

  <cygwin base dir>\usr\X11R6\bin\startxwin.bat
  

  where <cygwin base dir> is wherever you installed cygwin. This should bring up a window with an X desktop in it.
• from a terminal window on the X desktop, run an ssh command of the form:

  ssh -X -l <username> <host address>
  

  the -X tells ssh to do magic X port forwarding.
• in the new ssh session run an X program, e.g.:

  xterm &
  

• and away you go

I tried running Synaptic Package Manager from this, i.e.

sudo synaptic &

and it worked, a bit sluggishly, until it got to the point where I tried to accept changes and install packages, where it died with an X error. It did this twice so it is probably a deep X problem. I will have to stick with dselect

Got Ubuntu running fluxbox desktop manager instead of gnome:

• install fluxbox via dselect or apt:

  sudo apt-get install fluxbox
  

• edit ~/.xsession and add the following:

  exec /usr/bin/fluxbox
  

Installed Ubuntu linux. Posting this from Firefox running on Ubuntu.

The installer created a version that worked pretty much automatically. The only tweeks I had to do are:

• the installer hardware detection could not find my old dlink de220 ne2000 compatible ISA network card. I had to switch terminals and run:

  modprobe ne io=0x300 irq=9
  

  switching back to the installer, it found the network and was happy. It downloaded a load of updated modules from somewhere via the nerwork. It configured everything via DHCP, even found the name servers.
• Once Ubuntu was installed it ran ok but network was dead again. I had to edit /etc/modules to add the line

  ne io=0x300 irq=9
  

  and restart (although a modprobe would probably have done the trick).
• I used the network manager to change from the DHCP setup to a manual one so server has a static IP address.
• I edited /etc/apt/sources.list to add a 'universe' repository so I could use the Synaptic package manager to install packages unapproved by Ubuntu. This allowed me to install xawtv. I also installed 83 module updates.
• Ran xawtv from the command line and it Just Worked: the hardware detection had found my Pinnacle PCTV Rave and loaded all the bttv modules. Ubuntu seems to use a 2.6 kernel, hence my old problems were resolved.

Ubuntu observations:

• Don't like the brown colour scheme.
• root account is disabled! Everything has to be done via sudo. Apparently Max OS/X works this way. I was able to edit the config files above using 'sudo vim '. Sudo keeps prompting for passwords.
• Synaptic package manager looks nice, nicer than dselect (old text based apt tool I used to use on debian with weird key assignments).
• Samba network client Just Worked: was able to find Windows XP pc and poke around.
• Not bowled over by the documentation on the Ubunto web site. Mostly Wiki notes, often directing me to Room 101, a catchall.
• Modern X has much nicer fonts than Suse 6.4 vintage.

Did background update of home server using dselect via ssh. Something like 63 packages were upgraded, things like nfs and openoffice dictionary that I don't need. SSL update said a restart was advised so I rebooted the box. It hasn't rebooted, it's offline. What can be wrong?

Played some more with dselect. It upgraded a load more stuff for me, including font stuff which should be useless on a console system.

Installed vim-python which is vim with integrated python. It Just Worked.

Installed qpopper which appears to be THE pop server. It Just Worked. I could use it to receive email on the laptop. I managed to send email via the server as well, although I had to enable relaying for the laptop's ip address. Looking at the headers, the isp has added a warning about the message originating from a dialup. Cheek.

Anyway, the pop gives me limitless email accounts.

Dselect finished it's update after waiting all night to the answer to a question. It asks lots of questions at odd intervals so needs supervision. The questions are things like whether I want to reboot the pcmcia card manager: not totally obvious stuff. I think it has upgraded everything to the latest unstable versions: gee thanks.

I rebooted it and everything is still alive so I am happy and still glad I went for Debian.