Shrink An Encrypted LUKS Partition - Revision history

Dlk at 14:05, 31 December 2019

2019-12-31T14:05:22Z

Dlk: Dlk moved page Shrink A Partition to Shrink An Encrypted LUKS Partition without leaving a redirect

2019-12-31T13:00:28Z

Dlk moved page Shrink A Partition to Shrink An Encrypted LUKS Partition without leaving a redirect

Dlk at 12:59, 31 December 2019

2019-12-31T12:59:47Z

Dlk at 12:24, 21 May 2011

2011-05-21T12:24:17Z

Dlk at 12:23, 21 May 2011

2011-05-21T12:23:20Z

Dlk at 02:34, 9 May 2011

2011-05-09T02:34:33Z

Dlk at 02:33, 9 May 2011

2011-05-09T02:33:59Z

Dlk at 02:32, 9 May 2011

2011-05-09T02:32:40Z

Dlk at 02:30, 9 May 2011

2011-05-09T02:30:59Z

Dlk at 02:29, 9 May 2011

2011-05-09T02:29:01Z

← Older revision		Revision as of 14:05, 31 December 2019
Line 57:		Line 57:
	sudo resize2fs /dev/sda1		sudo resize2fs /dev/sda1
	[[Category:Linux]]		[[Category:Linux]]
		+	[[Category:Disks & Storage]]

← Older revision		Revision as of 12:59, 31 December 2019
Line 56:		Line 56:
	Expand the /boot partition to fill the available space. This can be done on a live partition as long as it's ext3, otherwise you'd have to boot back into Knoppix:		Expand the /boot partition to fill the available space. This can be done on a live partition as long as it's ext3, otherwise you'd have to boot back into Knoppix:
	sudo resize2fs /dev/sda1		sudo resize2fs /dev/sda1
		+	[[Category:Linux]]

@@ Line 53: / Line 53: @@
    /dev/sda2         3665352   976773167   486553908   83  Linux
 Reboot while praying.  (This is why you make that clone copy of the disk at the beginning.  Use dd_rescue to put the disk back the way it was if you need to.)
-<br />Expand the /boot partition to fill the available space.  This can be done on a live partition as long as it's ext3, otherwise you'd have to boot back into Knoppix:
    sudo resize2fs /dev/sda1

@@ Line 20: / Line 20: @@
 My guidance for this came from http://ubuntuforums.org/showthread.php?p=4530641
-Boot from Knoppix DVD, open a console and become root.
+Boot from [http://www.knoppix.net/ Knoppix DVD], open a console and become root.
 <br />Make a clone backup of the entire disk, just in case.  (In my case /dev/sdb was a USB disk of the same size as /dev/sda.)
    dd_rescue /dev/sda /dev/sdb

@@ Line 6: / Line 6: @@
    /dev/sda2          409663   976773167   488181752   83  Linux
-/dev/sda1 contains "/boot" as a native ext3 partition
+/dev/sda1 contains "/boot" as a native ext3 partition.
-/dev/sda2 is a LUKS encrypted partition, home to a Logical Volume Group which contains a logical swap partition and a logical partition which contains my root ("/") ext3 filesystem.
+<br />/dev/sda2 is a LUKS encrypted partition, home to a Logical Volume Group which contains a logical swap partition and a logical partition which contains my root ("/") ext3 filesystem.
 My steps were:

← Older revision	Revision as of 13:00, 31 December 2019
(No difference)

@@ Line 48: / Line 48: @@
 Move the /dev/sda2 partition data from where it is now to the end of the disk.  Start the copy from the end of the partition space and copy in reverse, from back to front.  This avoids overwriting the existing data until after we've copied it.  You only get one shot to get this right.
    dd_rescue -s 973517479b -S 976773167b -m 973107816b -r /dev/sda /dev/sda
-Use parted to redo the partition table to match the new /dev/sda2 start and end.  Also change /dev/sda1 so that it uses the free space.  (We don't use fdisk because it cannot handle partitions that start at the beginning of cylinder 1 / sector 63 as /dev/sda1 must.)
+Use parted to redo the partition table to match the new /dev/sda2 start and end.  Also change /dev/sda1 so that it uses the free space.  (We don't use fdisk because it cannot handle partitions that start at the beginning of cylinder 1 / sector 63 as /dev/sda1 must in order for the system to boot.)
       Device Boot      Start         End      Blocks   Id  System
    /dev/sda1   *          63     3662109     1831023+  83  Linux

@@ Line 46: / Line 46: @@
    vgchange -an
    cryptsetup luksClose crypt1
-Move the /dev/sda2 partition data from where it is now to the end of the disk.  Start the copy from the end of the partition space and copy in reverse, from back to front:
+Move the /dev/sda2 partition data from where it is now to the end of the disk.  Start the copy from the end of the partition space and copy in reverse, from back to front.  This avoids overwriting the existing data until after we've copied it.  You only get one shot to get this right.
    dd_rescue -s 973517479b -S 976773167b -m 973107816b -r /dev/sda /dev/sda
 Use parted to redo the partition table to match the new /dev/sda2 start and end.  Also change /dev/sda1 so that it uses the free space.  (We don't use fdisk because it cannot handle partitions that start at the beginning of cylinder 1 / sector 63 as /dev/sda1 must.)

@@ Line 20: / Line 20: @@
 My guidance for this came from http://ubuntuforums.org/showthread.php?p=4530641
-Boot from Knoppix DVD, open a console and become root
+Boot from Knoppix DVD, open a console and become root.
-<br />Make a clone backup of the entire disk, just in case
+<br />Make a clone backup of the entire disk, just in case:
    dd_rescue /dev/sda /dev/sdb
 Decrypt the LUKS partition:
@@ Line 32: / Line 32: @@
    resize2fs -p /dev/mapper/vg_dlkw500-lv_root -3255688s
    e2fsck -f /dev/mapper/vg_dlkw500-lv_root
-Shrink the volume group
+Shrink the volume group:
    lvdisplay
    lvreduce /dev/mapper/vg_dlkw500-lv_root -L -3255688s
    lvdisplay
-Shrink the LVM physical volume
+Shrink the LVM physical volume:
    pvs     # To see how much free space exists in the physical volume so that we can calculate the new size
    pvresize -setphysicalvolumesize 464G /dev/mapper/crypt1
    pvdisplay
-Shrink the encrypted disk area
+Shrink the encrypted disk area:
    cryptsetup status crypt1                         # Make note of the offset
    cryptsetup -o 4040 -b 973107816 resize crypt1    # 4040 is the offset, values are in 512B sectors
-Unmount the LVM and the encrypted area of the disk
+Unmount the LVM and the encrypted area of the disk:
    vgchange -an
    cryptsetup luksClose crypt1
-Move the /dev/sda2 partition data from where it is now to the end of the disk.  Start the copy from the end of the partition space and copy in reverse, from back to front.
+Move the /dev/sda2 partition data from where it is now to the end of the disk.  Start the copy from the end of the partition space and copy in reverse, from back to front:
    dd_rescue -s 973517479b -S 976773167b -m 973107816b -r /dev/sda /dev/sda
-Use parted to redo the partition table to match the new /dev/sda2 start and end.  Also change /dev/sda1 so that it uses the free space.  (We don't use fdisk because it cannot handle partitions that start at the beginning of cylinder 1 / sector 63 as /dev/sda1 must)
+Use parted to redo the partition table to match the new /dev/sda2 start and end.  Also change /dev/sda1 so that it uses the free space.  (We don't use fdisk because it cannot handle partitions that start at the beginning of cylinder 1 / sector 63 as /dev/sda1 must.)
       Device Boot      Start         End      Blocks   Id  System
    /dev/sda1   *          63     3662109     1831023+  83  Linux
    /dev/sda2         3665352   976773167   486553908   83  Linux
-Reboot while praying  (This is why you make that clone copy of the disk at the beginning.  Use dd_rescue to put the disk back the way it was if you need to.)
+Reboot while praying.  (This is why you make that clone copy of the disk at the beginning.  Use dd_rescue to put the disk back the way it was if you need to.)
-<br />Expand the /boot partition to fill the available space.  This can be done on a live partition as long as it's ext3, otherwise you'd have to boot back into Knoppix.
+<br />Expand the /boot partition to fill the available space.  This can be done on a live partition as long as it's ext3, otherwise you'd have to boot back into Knoppix:
    sudo resize2fs /dev/sda1