To recover OES file system with Logical Volume Manager (LVM), make sure to backup the required LVM data and obtain the configuration information of the original system.
About This Task
The section below illustrates the original configuration information needed for a recovery on a Red Hat 5.4 system. For simplicity, the new system hardware in this example is the same as the old system. The following steps should be performed only from the console.
Procedure
The following commands illustrate the types of data that need to be backed up to ensure a successful LVM restore.
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save /etc/fstab
[root ~]# cat /etc/fstab
/dev/VolGroup01/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/VolGroup01/LogVol01 swap swap defaults 0 0
/dev/mapper/xyzzy-space /space ext3 acl,user_xattr,defaults 0 0
/dev/mapper/xyzzy-extra /extra ext3 acl,user_xattr,defaults 0 0
/dev/sdb1 /ext3 ext3 acl,user_xattr,defaults 0 0
[root ~]#
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save contents of /proc/partitions
[root ~]# cat /proc/partitions
major minor #blocks name
8 0 8388608 sda
8 1 104391 sda1
8 2 8281507 sda2
8 16 8388608 sdb
8 17 8385898 sdb1
8 32 8388608 sdc
253 0 7208960 dm-0
253 1 1048576 dm-1
253 2 3891200 dm-2
253 3 4493312 dm-3
[root ~]#
[root ~]# fdisk -l
Disk /dev/sda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 1 13 104391 83 Linux
/dev/sda2 14 1044 8281507+ 8e Linux LVM
Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1044 8385898+ 83 Linux
Disk /dev/sdc: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 1044 8385898+ 83 Linux
[root ~]#
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The interactive lvm command provides information of the configuration and status of the logical volumes. Individual commands, such as pvcreate to get the UUID’s of LVM disks, vgdisplay and lvdisplay can also be used.
[root ~]# lvm
lvm>
lvm> vgdisplay -v
Finding all volume groups
Finding volume group "VolGroup01"
--- Volume group ---
VG Name VolGroup01
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 7.88 GB
PE Size 32.00 MB
Total PE 252
Alloc PE / Size 252 / 7.88 GB
Free PE / Size 0 / 0
VG UUID XTR8Sr-gcqw-WtKM-bi4a-fctP-0xH9-7vTsB0
--- Logical volume ---
LV Name /dev/VolGroup01/LogVol00
VG Name VolGroup01
LV UUID q00hUf-Xqt5-ZcL4-rErN-xEmp-EgTB-vdvdwD
LV Write Access read/write
LV Status available
# open 1
LV Size 6.88 GB
Current LE 220
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup01/LogVol01
VG Name VolGroup01
LV UUID 3A5SeG-PKUn-DaRm-0Bac-NPta-RdkB-N1Vx9P
LV Write Access read/write
LV Status available
# open 1
LV Size 1.00 GB
Current LE 32
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Physical volumes ---
PV Name /dev/sda2
PV UUID W0Y0cc-g4z1-ScQd-584L-40gR-I67d-YMuQih
PV Status allocatable
Total PE / Free PE 252 / 0
For example, to find volume group "xyzzy":
--- Volume group ---
VG Name xyzzy
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 8.00 GB
PE Size 4.00 MB
Total PE 2047
Alloc PE / Size 2047 / 8.00 GB
Free PE / Size 0 / 0
VG UUID mRiLOx-Ehbl-upEX-bxzf-EGDS-UTiL-vIb8qt
--- Logical volume ---
LV Name /dev/xyzzy/space
VG Name xyzzy
LV UUID R2DKYD-ljJP-nVfI-s1Gj-NgZi-glVb-XURMyS
LV Write Access read/write
LV Status available
# open 1
LV Size 3.71 GB
Current LE 950
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
--- Logical volume ---
LV Name /dev/xyzzy/extra
VG Name xyzzy
LV UUID RtkNPS-FCcy-WOko-gSlc-J48d-Dq0J-YCnM5x
LV Write Access read/write
LV Status available
# open 1
LV Size 4.29 GB
Current LE 1097
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3
--- Physical volumes ---
PV Name /dev/sdc
PV UUID BftPia-mJZY-8eHA-BMNf-Jv38-Mbnl-bN5ej6
PV Status allocatable
Total PE / Free PE 2047 / 0
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Exit from lvm
vm> quit
Exiting....
[root ~]#
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The original system has three disks partitioned as follows:
/dev/sda2 – Volume Group “VolGroup01-LogVol00” (root)
/dev/sda2 – Volume Group “VolGroup01-LogVol01” (swap)
/dev/sda1 - /boot
/dev/sdb1 – standard ext3 file system mounted on /ext3
/dev/sdc1 – Volume group “xyzzy”. Just a standard volume group with two logical volumes mounted to /extra and /space
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Perform a full system (Default) backup
vgcfgbackup –f <%s.VG_backup>
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Save the current Volume Group information. Copy the output files on another box. The e %s will be replaced with the VG name being backed up. One VG will be saved per file. The parameters of the command may vary depending upon the distribution you are using.
Result
In our example two files are created: VolGroup00.VG_backupxyzzy.VG_backup