Linux Corner

[rgbrock1]

Saab:

Mandriva has very good support for most, if not all, drivers of WPA and WPA2 enabled cards.

FWIW: 2nd on the list of Linux distros that I find work mostly out of the box is OpenSuSE.

[Cheerio]

Opensuse 11.2 was released yesterday. I'll install it tonight.

[x213a]

Have just upgraded to Ubuntu 9.10. I dont have any of the flash-player / DVD playback problems I experienced with 9.04. I presume all the required codecs came bundled with it. A definite improvement from my point of view - but I'm only a "lite" user though and somebody more Linux savvy may find it a total different experience.

[four_two]

I'm going to post this problem I have with my Package Manager in Ubuntu in the hope that someone can point me towards resolving it.

Although I've been using Ubuntu- in its various versions- for a couple of years- I'm pretty clueless about it as an operating system but as it's been very tolerant of me, and reliable, that hasn't been a problem.

A few days ago the icon that relates to the Package Manager turned a nasty shade of red and when I hover my mouse over it I get the following error message :


“Error Opening the cache (E=Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/
gb.archive.ubuntu.com_dists_jaunty_universe_binary-i386_Packages, E the lists or status file could not be parsed or opened.)”
This usually means that your installed packages have unmet dependencies

I looked on the Ubuntu forums and found the same problem with some instructions to follow. For example in the Terminal try:

1)sudo apt-get update && sudo apt-get upgrade

2)Change the software source and enter sudo apt-get update && sudo apt-get install -f

With the result I've ended up with virtually the same snag.

Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/archive.canonical.com_ubuntu_dists_jaunty_partner_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

As things stand I can't keep my system up to date so if I can't fix it I will execute plan B (to reinstall Ubuntu usingJaunty Jackelope as opposed to the one previous).

If someone has any ideas to help me – and of course simple enough for me to understand - I would be grateful.

[bnt]

Looks like the problem described here, where the solution is just to delete those package files from disk. They get re-created when you Update again:

Code:

sudo rm /var/lib/apt/lists/* -vf
sudo apt-get update

[x213a]

Bnt...

Re: Your last..do you actually have a reference file for these sort of command line inputs or are they "fluent" to you? Did you learn from study, experience or from error?
What is the best way to "get" Linux?



I've only just sussed out sudo apt-get update!

[bnt]

Well, with any command, you have a basic reference right in the terminal: you just say "man <whatever>" e.g. "man apt-get". You pick up various things over time, and the Internet is a great help here. Otherwise, just get your hands dirty - but make backups before changing files.

It might help to remember that "Linux" really only refers to the kernel, the "engine" under the hood. Applications like apt-get, or X-Windows and anything running under are not core and can be changed. Even the shell where you enter commands (usually "bash") is optional, though Ubuntu installs a lot of these applications to make the system usable by mere mortals.

The various "package managers" - systems for installing and deleting applications - are among the major differences between competing Linux systems. Red Hat, Mandriva & some others use the Red Hat system (RPM), SuSE has its own system, while Debian-based systems such as Ubuntu use the DPKG system. The "apt" commands are a friendlier layer on top of the "dpkg" commands", and there are also X-Windows applications that make it even easier, such as Synaptic or the new Ubuntu Software Centre.

I admit to having been a little confused by "sudo" at first: put it in front of any command, and that command runs with root privileges, just by entering your own password. Isn't that a security risk? Yes, it is, but it's not automatically enabled for all users, just the first user you create during installation. The alternative to that is logging in as root, which could be seen as an even greater risk, since the root user really can do anything, including things that can kill the installation stone dead - and you can get blasé and careless about it. You can use "sudo" to enable the root account if you want, but I wouldn't, since "sudo" does the same job, one command at a time.

edit: I should add that the location of those files is not the kind of thing you'd figure out by yourself - except for the general idea that they'd be in the place generally recommended for an application's working files i.e. under /var. I don't think /var/lib/apt is ideal, though - I'd say /var/cache/apt would be better, alongside the downloaded packages. In other words, while there are guidelines, the exact location is set by the developer, not dictated by Linux itself.

[four_two]

Thank you very much bnt,the little red Package Manager icon has disappeared and I assume everything is now ok.

Well perhaps not everything as this was tacked on to the end.



W: Failed to fetch cdrom://Ubuntu 9.10 iso Image/dists/karmic/main/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs

W: Failed to fetch cdrom://Ubuntu 9.10 iso Image/dists/karmic/restricted/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs

E: Some index files failed to download, they have been ignored, or old ones used instead.


So flushed with success I entered apt-cdrom and got the following(I thought in for a penny in for a pound) even if I didn't really know what it all meant.

~$ apt-cdrom
apt 0.7.20.2ubuntu6 for i386 compiled on Apr 17 2009 04:25:38
Usage: apt-cdrom [options] command

apt-cdrom is a tool to add CDROM's to APT's source list. The
CDROM mount point and device information is taken from apt.conf
and /etc/fstab.

Commands:
add - Add a CDROM
ident - Report the identity of a CDROM

Options:
-h This help text
-d CD-ROM mount point
-r Rename a recognized CD-ROM
-m No mounting
-f Fast mode, don't check package files
-a Thorough scan mode
-c=? Read this configuration file
-o=? Set an arbitrary configuration option, eg -o dir::cache=/tmp
See fstab(5)

I think it's referring to the download I had of Ubuntu ISO Image 9.10 on my desktop- in anticipation of having to reinstall Ubuntu if I was unable to get help for my problem.

As far as I can see - because I put a cd in my player - the player is recognised, and plays.

Thanks again for your help, although I did try the Ubuntu forums I think I might have tried in the wrong forum.

[bnt]

Yep - it was looking for a CD (or image) that wasn't where it was expected. I'm guessing you had the downloaded ISO image mounted to look like a CD (which is convenient) It's annoying but not fatal. If you want it to stop doing that, you can launch Synaptic, go to Repositories, and un-check the line that points at the CD. Or, if feeling adventurous, do this in the terminal:

Code:

sudo nano /etc/apt/sources.list

sudo we already discussed: nano is a simple text editor, and the rest is the file to edit. Scroll down till you find the line with "cdrom" in it, and put a # in front of it on the same line. This serves to "comment out" the line, like the old DOS "REM" command. When done, hit Ctrl-O to save the file, hit Enter to accept the name), and Ctrl-X to exit to the terminal. Do another sudo apt-get update afterwards to refresh the repositories.

Personally, I really like the apt-get system - it's one reason why I stick with Ubuntu, though I know other Debian-based distros have it too.

[four_two]

I'm probably going to make myself look foolish here but I went the terminal route, typed in sudo nano /etc/apt/sources.list and put a hash on the correct line then entered ctrl-o and ctrl-x and I get this:
File Name to Write: /etc/apt/sources.list....*
(This is shown in white on black at bottom)
If I were to try to exit by closing the terminal it says "a process is still running."
*Do I put in the apt-get update in here?

[bnt]

Sorry - that was from memory. The "file name to write" step is there in case you want to write to another file name. In this case you don't, so you just hit Enter to save to the same file name. Then it's Ctrl-X to exit to the terminal before you enter any more commands.

[rgbrock1]

In addition to using the 'man' command at the terminal for help with commands, syntax, qualifiers etc., I offer this other, hopefully helpful, qualifier to 'man'.

#man -k

The -k qualifier is used to search all short descriptions and manual page names for a keyword. And then prints out any matches.

Example. Say you're looking for help on something to do with rpm but you're not sure exactly which 'man' page would be applicable.

You would enter #man -k rpm

Which would then return all the 'man' pages having to do with the rpm package manager.

I find the -k qualifier handy when looking for a man page I'm sure exists but not sure of its exact spelling.

Hope this is helpful. To someone anyway!!

[four_two]

Originally Posted by bnt

Sorry - that was from memory. The "file name to write" step is there in case you want to write to another file name. In this case you don't, so you just hit Enter to save to the same file name. Then it's Ctrl-X to exit to the terminal before you enter any more commands.

Thanks for your help everything is back to normal now. So nice to see updates happening once again.

[bnt]

So, do we think this thread is worth a Sticky?

[mixture]

So, do we think this thread is worth a Sticky?

I do believe the mods made it clear that like the ex-Mac sticky, the thread should live and die based upon its own popularity.

I agree with that policy. Therefore no sticky would be my vote.

[x213a]

A while ago I posted a thread about being unable to installed Windows 7 on a laptop HDD that had a corrupted installation of Ubuntu on it. Nothing would let be wipe it or delete partitions. Everybody agreed it was buggered etc.
I have solved it. Heres how I did it:

I ran Testdisk off the Ultimate boot CD and analysed the disk. It showed various errors. One of the options presented to me was "recover superblocks". I did not, and still dont really know what they are but as I had nothing to lose I clicked it and away it went...
I was then able to scan the disk again and recover bad sectors. After that I was able to format the disk and install operating systems on it again.

Hope that helps somebody

Incidentally, just discovered a new bug on Ubuntu 9.10...It would not let me add application launchers to the desktop. The problem went away after a restart and I had about 20 open office icons on my desktop from my previous attempts. Anybody else encountered this?

[mad_jock]

Sounds like your desktop process hung not a problem with the OS a such more the desktop. Which one was it?

As for the super blocks did you try beating the disk to death with Fdisk and advanced options?

[bnt]

Those errors from TestDisk about superblocks - they only refer to the partition already on the disk, which is probably ext3 since Linux was on it. However, since the plan was to install Windows on that disk, there's zero point in worrying about that ext3 partition, since Windows can't use it and will expect you to delete it during installation. It's toast.

The only sensible option is to use fdisk on it, like mad_jock says, or a low-level format option. The Windows 7 installation is going to do this anyway, if it can, but I remember when I tried Vista a few years ago it couldn't recognise what was on a disk before and refused to wipe it - probably as a safety feature. I had to boot from a Linux "live" CD and wipe the disk. I call that the Aliens strategy: take off and nuke the thing from orbit. It's the only way to be sure.

[x213a]

Fdisk did not work and the live CD didnt either. It loaded but "hung" when re-partitioning. It would not let me delete partitions or change file system type or format either. I/O errors was the reason.

[mad_jock]

Right here is one for you all. A situation that someone wants me to define a solution for. And mods don't worry it's for an old aged pensioner to get an emergency call system working. They only have access to an anal retentive ISP which has the IP address down as a VoIP site and a 3G dongle isn't cutting the mustard. Its based in the UK and to my knowledge completely legal to do.

Situation

A certain box needs to get access to an IP address which is blocked by the ISP.

What I propose is connect said box via a cross over cable to a linux box via the eth0.

Then route that over to the wireless wlan0 which has a vpn connection on it thus bypassing the ISP blocked sites.

The dhcp on the eth0 is easy to take care of with the gateway being defined as the IP address being bound to the eth0 interface.

Now anyone know enough about openvpn on linux so you can force it to only use the wlan0 or will it just try both interfaces and use the one which it can connect to the server on?

after that I presume you would only need to start the routing using ip_forward and add the route in between the 2 networks.

Any comments on my cunning plan?

I know you could just buy a wireless VPN router but this way we should just be able to use an old laptop and a 3 quid cross over cable.