Using rysync to mirror entire system - what to omit

[lhbradley]

I have two identical hard drives, and have used dd to make one a duplicate of the boot drive.

I have set up rsync (as root) to run nightly to mirror the backup drive from the boot drive. There are a bunch of directories/files that fail (mainly is /sys) due to lack of permission - some of the sys files are write-only.

Can someone suggest what directories I can exclude from the mirroring?

I would like to be able to either boot the backup drive in case of a boot drive failure, or reinstall Ubuntu on a new disk, then copy the files back from the backup (or use dd, or whatever)

Any thoughts?

Thanks

[reed9]

/sys and /proc are virtual filesystems that provide info on the kernel, devices, drivers, processes, etc. Both can be excluded.

In general I would say it's easier and probably faster to reinstall that re-copy everything. I just backup configuration files and of course personal files. So my whole /home directory and then /etc and possibly /root if you've configured anything there for the root user.

Beyond that, I backup a list of installed packages for easy reinstallation. How to do this depends on your package manager. For example in Ubuntu you can do

sudo dpkg --get-selections > installed-applications.txt

and reinstall with

sudo dpkg --set-selections < installed-applications.txt
sudo apt-get -y update
sudo apt-get dselect-upgrade

For Arch I use

pacman -Qqe > installed-packages.txt

and can reinstall with

pacman -S $(< installed-packages.txt)

If you have limited bandwith or a slow internet connection, you might want to backup the package cache. Again, the location varies distro to distro, but should be in /var somewhere. I think Ubuntu is /var/cache/apt/archives.

[lhbradley]

/sys and /proc are virtual filesystems that provide info on the kernel, devices, drivers, processes, etc. Both can be excluded.

In general I would say it's easier and probably faster to reinstall that re-copy everything. I just backup configuration files and of course personal files. So my whole /home directory and then /etc and possibly /root if you've configured anything there for the root user.

Beyond that, I backup a list of installed packages for easy reinstallation. How to do this depends on your package manager. For example in Ubuntu you can do

sudo dpkg --get-selections > installed-applications.txt

and reinstall with

sudo dpkg --set-selections < installed-applications.txt
sudo apt-get -y update
sudo apt-get dselect-upgrade

For Arch I use

pacman -Qqe > installed-packages.txt

and can reinstall with

pacman -S $(< installed-packages.txt)

If you have limited bandwith or a slow internet connection, you might want to backup the package cache. Again, the location varies distro to distro, but should be in /var somewhere. I think Ubuntu is /var/cache/apt/archives.

Thanks!. I will have to test the procedure out on a spare disk drive, to be sure it works.

Larry