Extract partition data from xen image file - Revision history

Hemant: /* GETTING DATA FROM XEN IMAGE FILE */

2014-02-22T15:20:05Z

GETTING DATA FROM XEN IMAGE FILE

← Older revision		Revision as of 15:20, 22 February 2014
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	~~using kpartx utility~~

	# losetup -f ~~[find unused loop files ]~~		== using kpartx utility ==


			# losetup -f
	/dev/loop0		/dev/loop0

			'''This shows the avialable physical loop file/device that is unused and can be used to add a loop device
			'''

	#losetup /dev/loop0 /HDD_500/images/javapostgresql.img		#losetup /dev/loop0 /HDD_500/images/javapostgresql.img

			'''Associated the image file to loop file/device
			'''

	#kpartx -av /dev/loop0		#kpartx -av /dev/loop0

	add map ~~loop1p1~~ : 0 1024000 linear /dev/~~loop1~~ 2048		add map loop0p1 : 0 1024000 linear /dev/loop0 2048
	add map ~~loop1p2~~ : 0 60413952 linear /dev/~~loop1~~ 1026048		add map loop0p2 : 0 60413952 linear /dev/loop0 1026048

			'''This command reads partition tables on specified device and create device
			maps over partitions segments detected'''


	#losetup -a [lists all used loop files ]		#losetup -a [lists all used loop files ]

	/dev/loop0: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)		/dev/loop0: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)
	~~/dev/loop1: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)~~

	#vgscan		#vgscan
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	2 logical volume(s) in volume group "VolGroup" now active		2 logical volume(s) in volume group "VolGroup" now active

			'''activate and deactivate VolumeGroupName, or all volume groups if none is specified.'''

	#lvs		#lvs
	LV VG Attr LSize Origin Snap% Move Log Copy% Convert		LV VG Attr LSize Origin Snap% Move Log Copy% Convert

Hemant: /* GETTING DATA FROM XEN IMAGE FILE */

2014-02-22T15:11:31Z

GETTING DATA FROM XEN IMAGE FILE

← Older revision		Revision as of 15:11, 22 February 2014
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	using kpartx utility		using kpartx utility

	# losetup -f -- find unused		# losetup -f [find unused loop files ]
	/dev/loop0		/dev/loop0

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	#kpartx -av /dev/loop0		#kpartx -av /dev/loop0

	add map loop1p1 : 0 1024000 linear /dev/loop1 2048		add map loop1p1 : 0 1024000 linear /dev/loop1 2048
	add map loop1p2 : 0 60413952 linear /dev/loop1 1026048		add map loop1p2 : 0 60413952 linear /dev/loop1 1026048

	#losetup -a ~~---~~lists all used		#losetup -a [lists all used loop files ]

	/dev/loop0: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)		/dev/loop0: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)
	/dev/loop1: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)		/dev/loop1: [0811]:32571394 (/HDD_500GB/images/javapostgresql.img)
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	#kpartx -d /dev/loop0		#kpartx -d /dev/loop0

	#losetup -d /dev/loop0 --delete from used		#losetup -d /dev/loop0 [delete from used]

	NOTE: always remember to deactivate the logical volumes with "vgchange -an", remove the partitions with "kpartx -d", and (if appropriate) delete the loop device with "losetup -d" after you are finished. There are two reasons: first of all, the default volume group name for a install is always the same, so if you end up activating two disk images at the same time you'll end up with two separate LVM volume groups with the same name. LVM will cope as best it can, but you won't be able to distinguish between these two groups on the command line.		NOTE: always remember to deactivate the logical volumes with "vgchange -an", remove the partitions with "kpartx -d", and (if appropriate) delete the loop device with "losetup -d" after you are finished. There are two reasons: first of all, the default volume group name for a install is always the same, so if you end up activating two disk images at the same time you'll end up with two separate LVM volume groups with the same name. LVM will cope as best it can, but you won't be able to distinguish between these two groups on the command line.

	And secondly, if you don't deactivate it, then if the guest is started up again, you might end up with the LVM being active in both the guest and the dom0 at the same time, and this may lead to VG or filesystem corruption.		And secondly, if you don't deactivate it, then if the guest is started up again, you might end up with the LVM being active in both the guest and the dom0 at the same time, and this may lead to VG or filesystem corruption.

Hemant: /* GETTING DATA FROM XEN IMAGE FILE */

2014-02-22T14:41:38Z

GETTING DATA FROM XEN IMAGE FILE

← Older revision		Revision as of 14:41, 22 February 2014
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	#vgchange -an VolGroup		#vgchange -an VolGroup
	0 logical volume(s) in volume group "VolGroup" now active		0 logical volume(s) in volume group "VolGroup" now active


			#kpartx -d /dev/loop0

	#losetup -d /dev/loop0 --delete from used		#losetup -d /dev/loop0 --delete from used

Hemant: /* GETTING DATA FROM XEN IMAGE FILE */

2014-02-22T12:16:27Z

GETTING DATA FROM XEN IMAGE FILE

@@ Line 11: / Line 11: @@
 using kpartx utility
-# losetup -f
+# losetup -f  -- find unused
 /dev/loop0
@@ Line 19: / Line 19: @@
 add map loop1p1 : 0 1024000 linear /dev/loop1 2048
 add map loop1p2 : 0 60413952 linear /dev/loop1 1026048
 #vgscan
@@ Line 38: / Line 42: @@
 NOW you can access your root partition in image on /mnt/data folder

Hemant: Created page with "THE ISSUE WAS FACED ON 192.168.1.15 where a virtual machine had boot error : ERROR: boot loader didn't return any data! The virtual machine was not getting up so data has to..."

2014-02-22T11:49:17Z

Created page with "THE ISSUE WAS FACED ON 192.168.1.15 where a virtual machine had boot error : ERROR: boot loader didn't return any data! The virtual machine was not getting up so data has to..."

New page

THE ISSUE WAS FACED ON 192.168.1.15 where a virtual machine had boot error :

ERROR: boot loader didn't return any data!

The virtual machine was not getting up so data has to be extracted

== GETTING DATA FROM XEN IMAGE FILE ==

using kpartx utility

# losetup -f
/dev/loop0

#losetup /dev/loop0 /HDD_500/images/javapostgresql.img

#kpartx -av /dev/loop0
add map loop1p1 : 0 1024000 linear /dev/loop1 2048
add map loop1p2 : 0 60413952 linear /dev/loop1 1026048

#vgscan

Reading all physical volumes. This may take a while...
Found volume group "VolGroup" using metadata type lvm2

#vgchange -ay VolGroup
2 logical volume(s) in volume group "VolGroup" now active

#lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv_root VolGroup -wi-a- 27.80G
lv_swap VolGroup -wi-a- 1.00G

#mount /dev/VolGroup/lv_root /mnt/data/

NOW you can access your root partition in image on /mnt/data folder