27Jul/100
Recovering deleted lvm volume
LVM is a logical volume manager for the Linux kernel; it manages disk drives and similar mass-storage devices, in particular large ones. The term "volume" refers to a disk drive or partition thereof.
Every LVM operation makes backup of lvm metadata. Metadata archive stored in directory /etc/lvm/archive/ in easily readable text files. Each operation creates own metadata backup file, with information when it was created. For example:
# Generated by LVM2 version 2.02.39 (2008-06-27): Fri Feb 5 21:15:12 2010
contents = "Text Format Volume Group"
version = 1
description = "Created *before* executing 'lvcreate -L4G -n test data'"
creation_host = "avenger.iwik.org" # Linux avenger.iwik.org 2.6.28-11-server #42-Ubuntu SMP Fri Apr 17 02:48:10 UTC 2009 i686
creation_time = 1265400912 # Fri Feb 5 21:15:12 2010
data {
id = "ypogpf-ONt1-36Jh-xXXp-a3UN-Pjyt-wLn1zx"
seqno = 19
status = ["RESIZEABLE", "READ", "WRITE"]
extent_size = 8192 # 4 Megabytes
max_lv = 0
max_pv = 0
physical_volumes {
pv0 {
id = "5n3lo9-S52y-3rTQ-3rP5-zfEC-irkg-OSRL3n"
device = "/dev/md2" # Hint only
status = ["ALLOCATABLE"]
dev_size = 1930081024 # 920.334 Gigabytes
pe_start = 384
pe_count = 235605 # 920.332 Gigabytes
}
}
logical_volumes {
home {
id = "hyh3yU-jXr7-FMLT-ZxNY-ci50-L5e6-IGC3aM"
status = ["READ", "WRITE", "VISIBLE"]
segment_count = 1
segment1 {
start_extent = 0
extent_count = 65280 # 255 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 0
]
}
}
var {
id = "0iOAxf-DhPG-T1Pk-3Qr1-Sqy5-XsKz-KyyCvo"
status = ["READ", "WRITE", "VISIBLE"]
segment_count = 1
segment1 {
start_extent = 0
extent_count = 3840 # 15 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 153600
]
}
}
...
}
}
}
Using correct backup file, lvm configuration can be easily recovered using vgcfgrestore command. If you deleted logical volume(s) or volume group, you can easily recover them back.