Which directories of a Gentoo system to back up?

[ayqazi]

Hi,

I want to back up my Gentoo system. I need to know which directories I can leave out, since they will be regenerated at boot if I have to restore a backup.

I'm NOT backing up my /home directory, since that's on a separate partition, and I can simply log on as root, mount -o ro,remount /home and then back it up.

So, not counting home, here's the directories I'm not going to back up, and I'd like your comments on it:
/var/log : regenerated when syslog-ng starts?
/tmp: obvious reasons
/var/tmp: obvious reasons

/usr/portage/distfiles: don't need this, do I?

I'm thinking of /usr/portage/distfiles - shouldn't it be somewhere else by default? like /var/portage/distfiles? /usr could be mounted read-only, after all.

Thanks

[frostschutz]

[Ferdinando]

[frostschutz]

PS: If you're *really really really* low on backup space, you could also leave out all system binaries and programs that were generated by Portage, and keep just the dynamic data (Portage database, other stuff in /var, and whatever else you have). For a full restauration of the system, you'd then have to re-emerge all programs you had installed before (emerge -e world, you can get a working emerge by doing a basic Gentoo Stage installation). This way the procedure will take some time though.

[ayqazi]

Point taken on /var/log, but backing them up while the system is running seems a bit too.... sorry, I've been using Linux for 10 years or so, and I'm still nervous about touching in-use files. ME BAD, ME BAD *slap*

As for the last point about just dynamic data - I'm not going through that installation process again! :-)

And point taken about not being able to update portage if /usr is readonly - which makes me wonder, wouldn't /var/portage have been a better location for the portage tree? And /usr/local/var/portage the overlay? /var being where dynamic system data is kept by standard? Doesn't matter really, just nitpicking....

Thanks - will start 'tar --multi-volume'ing onto iso images that then go onto DVDs ASAP, and will include /var/log :-)

[frostschutz]

Well, it's a question of style, and can not be really answered.

Is the Portage tree dynamic data? Actually, it's pretty static - it only changes when you want to update your system, and when you do that, other packages will change too (as they get replaced by a new version), so in a sense, everything is dynamic and everything isn't. From another point of view, it is static as well, because it's man-made, not randomly generated by some logging facility or random acts of user. From a practical point of view, the main reason not to put it in var is that var contains mostly very important data (like the Portage database, user mails, etc), and I prefer it to be small and light so I can back it up fast and frequently. I don't need another 500MB of Portage in there, thanks.

As far as I know, pretty much all paths and stuff can be set in make.conf, so you're free to change whatever you do not like.

[opopanax]