Reinstalling Ubuntu without formatting partition - what folders are deleted?
Solution 1:
I wasn't able to find a hardcoded list in the ubiquity source code. The documentation says that partitioning is handled by d-i (debian installer) code to avoid duplication and maintenance effort. But I wasn't able to find an answer in the related packages or the Debian documentation.
Fortunately /var/log/syslog, respectively /var/log/installer/syslog post installation, contains useful information about ubiquity and the installation process. Here is an excerpt from a 12.04 install over a 12.04 install in my VM:
May 27 21:20:12 ubuntu ubiquity[8109]: switched to page partman
May 27 21:20:35 ubiquity[8109]: last message repeated 5 times
May 27 21:20:35 ubuntu kernel: [ 598.116238] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
May 27 21:20:35 ubuntu ubiquity: umount: /tmp/tmp.5jn9BTMDwz: device is busy.
May 27 21:20:35 ubuntu ubiquity: (In some cases useful info about processes that use
May 27 21:20:35 ubuntu ubiquity: the device is found by lsof(8) or fuser(1))
May 27 21:20:35 ubuntu ubiquity:
May 27 21:20:37 ubuntu ubiquity[8109]: debconffilter_done: ubi-partman (current: ubi-partman)
May 27 21:20:37 ubuntu ubiquity[8109]: Step_before = stepPartAdvanced
May 27 21:20:37 ubuntu clock-setup: Sun May 27 21:20:37 UTC 2012
May 27 21:20:37 ubuntu clock-setup: rdate: adjust local clock by -0.063701 seconds
May 27 21:20:40 ubuntu ubiquity[8109]: switched to page timezone
May 27 21:20:42 ubuntu kernel: [ 605.076359] Adding 784380k swap on /dev/sda5. Priority:-1 extents:1 across:784380k
May 27 21:20:42 ubuntu kernel: [ 605.225583] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
May 27 21:20:51 ubuntu ubiquity: not installable:
May 27 21:20:51 ubuntu ubiquity: version mismatch:
May 27 21:20:51 ubuntu clear_partitions: Considering /,/dev/sda1.
May 27 21:20:51 ubuntu kernel: [ 614.038996] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
May 27 21:20:51 ubuntu clear_partitions: Removing bin from / (/dev/sda1).
May 27 21:20:51 ubuntu clear_partitions: Removing dev from / (/dev/sda1).
May 27 21:20:51 ubuntu clear_partitions: Removing etc from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing lib from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing lib64 from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing proc from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing sbin from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing sys from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing usr/bin from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing usr/games from / (/dev/sda1).
May 27 21:20:52 ubuntu clear_partitions: Removing usr/include from / (/dev/sda1).
May 27 21:20:53 ubuntu clear_partitions: Removing usr/lib from / (/dev/sda1).
May 27 21:20:53 ubuntu clear_partitions: Removing usr/not-formatted from / (/dev/sda1).
May 27 21:20:53 ubuntu clear_partitions: Removing usr/sbin from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing usr/share from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/backups from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/cache from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/crash from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/games from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/lib from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/lock from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/log from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/mail from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/not-formatted from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/opt from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/run from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/spool from / (/dev/sda1).
May 27 21:21:02 ubuntu clear_partitions: Removing var/tmp from / (/dev/sda1).
May 27 21:21:02 ubuntu kernel: [ 625.522422] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: errors=remount-ro
Basically the directories bin, dev, etc, lib, lib32, lib64, proc, sbin and sys are deleted as are the contents of usr and var (/usr/local and /var/local seem to be an exception, but test folders I had in usr and var were deleted). The boot directory does not seem to be deleted and is just overwritten by the packages related to grub and the kernel.