What is the best way to make a reinstall?

PhotonX · 2011-04-25 09:54:07

Hello community!

I have noticed that my Arch machine is consuming quite much RAM and often even the swap gets full resulting in a complete freeze (1GB RAM and 1GB swap). I now want to make a 32Bit install (currently 64Bit) in the hope that it will handle the RAM a bit more economically.

I'd like to preserve the whole configuration of the system. /home is placed in an extra partition so the user settings will remain after the reinstall, but how to save the systemwide configuration? Maybe there is some tool (something like remastersys) which could take care of this?

Thanks,
PhotonX

d00maz · 2011-04-25 11:28:12

all of the system-wide configs are in /etc so i'd backup that.

demian · 2011-04-25 11:32:18

It's not that much work really which is why i don't think you'll find a tool to do it.
Usually you'd backup /etc, /boot and possibly /root for a "config backup".
When switching from 64 to 32bit you obviously can't just backup /usr so you'll have to reinstall all packages manually.
This command will give you the names of all the packages currently installed on your system in one line.

pacman -Q | awk '{printf "%s ", $1}'

If you wanted you could just type pacman -Sy in front of that line and reinstall all packages that way.

Last edited by demian (2011-04-25 11:37:30)

PhotonX · 2011-04-25 12:11:04

Thank you for your replies! I'll experiment on a second partition (for any case) and report.

edit: Shall I just remove the lib32-* packages from the list?

Last edited by PhotonX (2011-04-25 12:23:35)

demian · 2011-04-25 15:58:29

No use for them on a native 32bit Arch
So yeah, you can delete them from the list along with any package starting with lib. If libraries are needed they'll get downloaded as dependencies for other packages anyway. This way you'll probably leave out some long orphaned libraries meaning less bloat on your new system.

Last edited by demian (2011-04-25 16:03:24)

NSB-fr · 2011-04-25 19:08:39

I did a full system reinstall recently so I have a two tips for you concerning your installed package list :

Obtain a list of package explicitly installed (installed in a pacman -S command, not just pulled in as a dependency)

$ pacman -Qqe > explicitpackage.txt

Why explicit packages only ? Reinstalling the full list would make the full list explicitly installed. Think about the "pacman -Rs" command and you will guess why this is bad if you want to keep your system clean...

While at it and if you feel it may be necessary, take a look at the file and search for packages of the kind "I tried it and forgot about it but I don't need it anymore" I had tons of them !

Restore the package list on the new install

# pacman -S $(cat explicitpackage.txt)

If anything does not exist in 32bit repo (like any lib32) you will get an error. Just open and remove the offending lines.

Hope it will help.

demian · 2011-04-25 20:03:17

NSB-fr wrote:

Why explicit packages only ? Reinstalling the full list would make the full list explicitly installed. Think about the "pacman -Rs" command and you will guess why this is bad if you want to keep your system clean...

Right, i forgot about that. Definately better use "pacman -Qe". If you type "pacman -Rss" the removal will extend to explicitly installed packages too though.

NSB-fr · 2011-04-25 21:26:14

demian wrote:

Right, i forgot about that. Definately better use "pacman -Qe". If you type "pacman -Rss" the removal will extend to explicitly installed packages too though.

I was not aware of the -Rss option, thanks

PhotonX · 2011-04-28 07:11:42

Thanks for all the hints, I used the Qqe version and everything seemed to be fine. But unfortunately after a reboot the Gnome panel is missing and many applications fail to start with "cannot execute binary file". Also there are some warnings in the X session log complaining about a wrong elfclass (I think it was libogg.so and libcanberra-gtk.so) though the only things that are taken over from the 64 bit system are the /home directory and the /etc folder...

SanskritFritz · 2011-04-28 07:53:46

https://wiki.archlinux.org/index.php/Mi … installing

PhotonX · 2011-04-28 17:46:53

Thanks, this sounds really interesting, but after the freshly installed system is broken I'm a bit afraid to touch my productive system...

PhotonX · 2011-05-07 18:07:49

To give some feedback about the whole story: The "cannot execute binary file" things came from some file from the backed up /etc folder so I ended up with configuring the system once again (I think it's even better like this), while the "wrong elfclass things" seem to come from the multilib repo that I forgot to remove from the old pacman.conf file. So in fact I used only the package list and redid the configuration and now the new system is up and running.

Thanks again for your assistance,
PhotonX

Arch Linux

#1 2011-04-25 09:54:07

What is the best way to make a reinstall?

#2 2011-04-25 11:28:12

Re: What is the best way to make a reinstall?

#3 2011-04-25 11:32:18

Re: What is the best way to make a reinstall?

#4 2011-04-25 12:11:04

Re: What is the best way to make a reinstall?

#5 2011-04-25 15:58:29

Re: What is the best way to make a reinstall?

#6 2011-04-25 19:08:39

Re: What is the best way to make a reinstall?

#7 2011-04-25 20:03:17

Re: What is the best way to make a reinstall?

#8 2011-04-25 21:26:14

Re: What is the best way to make a reinstall?

#9 2011-04-28 07:11:42

Re: What is the best way to make a reinstall?

#10 2011-04-28 07:53:46

Re: What is the best way to make a reinstall?

#11 2011-04-28 17:46:53

Re: What is the best way to make a reinstall?

#12 2011-05-07 18:07:49

Re: What is the best way to make a reinstall?

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