[Bug 569201] Re: if an extended partition contains unallocated space before the first logical partition, the start of the extended partition is moved to start of first logical partition [first EBR is MOVED and affected MBR and EBR tables updated when no such partition changes are requested] (present in both GUI and text installers)

[Marcus Tomlinson]

This release of Ubuntu is no longer receiving maintenance updates. If
this is still an issue on a maintained version of Ubuntu please let us
know.

** Changed in: ubiquity (Ubuntu)
       Status: Confirmed => Incomplete

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to debian-installer in Ubuntu.
https://bugs.launchpad.net/bugs/569201

Title:
  if an extended partition contains unallocated space before the first
  logical partition, the start of the extended partition is moved to
  start of first logical partition [first EBR is MOVED and affected MBR
  and EBR tables updated when no such partition changes are requested]
  (present in both GUI and text installers)

Status in debian-installer package in Ubuntu:
  New
Status in partman-base package in Ubuntu:
  New
Status in ubiquity package in Ubuntu:
  Incomplete

Bug description:
  Binary package hint: ubiquity

  Disk is partitioned as follows using Microsoft DiskPart version 6.1.7600
  Primary1
  Primary2
  Primary3
  Logical1
  Logical2
  Logical3
  Logical4

  DiskPart creates MBR and EBR tables padded with hidden sectors and uses 2048 sectors in total (in contrast to the traditional 63)
  http://www.multibooters.co.uk/partitions.html

  Ubuntu install:
  During install 'specify partitions manually' is chosen.

  Partition Logical2 is changed: Ext4, format the partition, mount point /
  No other changes are made.

  At some point during installation the following changes are made to the partition tables:
  The EBR table preceding Logical1 is moved forward 2046 sectors toward the end of the hidden sectors created by DiskPart.
  The MBR is updated accordingly to reflect the new offset of the table and the reduced extended partition size (2046 sectors smaller).
  The EBR tables for Logical1 (now moved) Logical2 and Logical3 are changed to reflect the new offsets (reduced by 2046 sectors) of their proceeding respective extended partitions caused by moving the first EBR.

  Behaviour does not occur if Logical2 contains and existing Ext4
  filesystem. If Logical2 is filled with zeros then the EBR is moved.

  Why does this happen? Ubuntu was not instructed to make changes to my
  partition tables. It was instructions only to format a partition (it
  did not even have to change the partition ID).

  More to the point why the hell does this happen at all? There should
  be no reason to move the EBR table around like that!

  Probably related to this:
  https://bugs.launchpad.net/ubuntu/+source/partman-base/+bug/342485

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/debian-installer/+bug/569201/+subscriptions