Apt-get protection

**Rink** · 04-08-2004, 06:33 PM

Hi,

Attempted to install KDevelop3:

'apt-get -t unstable install kdevelop3'

The install failed with unmet dependencies, can't remember which ones, but the package needed some lib which was > that which was to be installed (from memory, the denomination was a slightly different format which might have confused things).

(My KDE install was shot after the with half the menus missing)

Anyway subsequent apt-get have failed and the advice from the system is to try 'apt-get -f install'

This I did, and was prompted that this would release 312Meg from my system (Y/N)

Typing yes released both barrells into an already shot system and rendered it unuseable!

I've reinstalled from Knoppix 3.3 but am anxious not to repeat the excercise.

I definately won't be installing kdevelop3, can you guys recommend a way for me not to fall into the same trap again. I mean, if apt-get does this on kdevelop3, will it behave in a similar way with another package.

is there any way to 'rollback' the install to the way it was?

Many thanks,

Dave Coventry

**OErjan** · 04-09-2004, 09:05 AM

you seem to have had bad luck.
I have had a few similar but no shot system though, just one or two programs not working well.
it seems the "unstable" is there for a reason...

**Rink** · 04-09-2004, 09:37 AM

>it seems the "unstable" is there for a reason.

Don't I know it!

Still, I generally feel it's worth the risk. The Authors of Knoppix seem to agree!

what I'm looking for is some way I can protect myself, a sort of clothesline I can trail behind me so that I can come back to the point at which I started if it all goes titsup.

**OErjan** · 04-09-2004, 10:46 AM

how much hddspace can you accept loosing for that?
if you hae a hdd partition "left oever" you could dd your system just prior to upgrade, it would take 2-4Gb iirc.
If you do that and all goes %¤%& you can then dd it back 100% untouched. i would use a dvd for it but not all have a dvd+rw writer so... partiton might have to do

**Rink** · 04-09-2004, 12:18 PM

>If you do that and all goes %¤%& you can then dd it back
>100% untouched. i would use a dvd for it but not all have a
>dvd+rw writer so... partiton might have to do

Yikes!

That's one way of doing it.

I recently installed a DVD writer (havn't installed any dvd writing modules, though, not sure where to get the required software) so that could be a possibility....

However, seems a bit of a drastic solution.

I way thinking more in terms of a log that gives a snapshot of which version of what is installed and other changes to the system, configuration files, etc (the clothesline I was talking about).

And some kind of a system that could Automagically use that information to rollback to where it was.

In the meantime, if I use the -s option on apt-get, will this highlight the sorts of issues that have killed my system previously?

**OErjan** · 04-09-2004, 06:00 PM

ok for the clothesline i can only give partial help.
but for DVD i can give much more

(further down)
too keep configs... of your user do a backup of your /home/users .files those are the config files, bookmarks, mail...
then do a backup of /etc (whole /etc is not more than 35-40M).
that is, in a console do
cp -avx /etc /apropriate/target&&cp -avx /home/user/.* /apropriate/target.
those would not be overly large together (depending on amount of mail and so)that should have 90+%of your configs. as for programe downgrading... someone else might help.
now to DVD.
i use a tool called dvd+rw-tool
it works both for + AND - r and rw rcording.
it is a console app but k3b for one can be used as a graphical frontend.
here is more info
http://fy.chalmers.se/~appro/linux/DVD+RW/
one great tool. actually only some 5 diferent comands to remember for most things

quote from the page above.

growisofs -Z /dev/scd0 -R -J /some/files
growisofs -M /dev/scd0 -R -J /more/files
growisofs -Z /dev/scd0=image.iso
f you wish to burn down output generated by an arbitrary program, you can use: dumpsomething | growisofs -Z /dev/scd0=/dev/fd/0

and finaly one from a forum (bbs.linux.se

osted by calvin95) and to burn dvdvideo . the opt/dvd is where the film is, please observe it needs to already BE the right structure.
growisofs -Z /dev/scd0 -dvd-video /opt/dvd

hope this helps
PS here is the actual program, http://fy.chalmers.se/~appro/linux/D...4.4.7.4.tar.gz.
DS

**OErjan** · 04-09-2004, 06:04 PM

there are aditional comands for blanking and formating but they are not used very often by me. as the dvd+rw is more or less a ext2 disc with a 4+GB capacity... it would be a option for you i think.

**Durand Hicks** · 04-09-2004, 07:45 PM

You can clothesline your system by open a console and type:
dpkg --get-selections > todaysdate.txt

That will give you a list of currently installed software, and if a majority were removed and you want it back, you can open a console as root and type:
dpkg --set-selections < todaysdate.txt.

Remember to do the get-selections clothesline everytime you do an upgrade, install software, or remove software. I can't tell you how many times I've tried this and it saved me headaches in tracking down what was installed and what wasn't installed based on a certain date. I realize this isn't the same as imaging your system, but it's great for taking a "snapshot" of installed software but not the settings or configuration, but to me, it's an acceptable tradeoff as I don't have to deal with removing junk vis-a-vis windows registry. Anyone who has used windows knows what I'm talking about, programs don't uninstall cleanly after themselves thus leaving us with an nearly impossible task of searching orphans in the registry and orphaned files left behind in various directories. With apt-get or dpkg, it makes it so simple, that I consider the microsoft way "stone-age computing". Back in the days of DOS, it was easy as deleting the directory the programs resided in.