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)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
debian-installer (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
partman-base (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
ubiquity (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
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://
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:/
description: | updated |
description: | updated |
summary: |
- extended boot record tables MOVED and modified when no partition changes - are requested + 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) |
Diagrammatic representation of changes