Docstoc

Linux Full System Restore from LVM to non-LVM

Document Sample
Linux Full System Restore from LVM to non-LVM Powered By Docstoc
					Example of Linux full system restore from
an lvm based install to a non-lvm based
system.
Published 02/17/2010 05:40 PM | Updated 02/21/2010 03:01 AM


This example will show an “In Place Restore” of a complete Linux OS that was initially
installed using lvm based storage to a new disk that does not have lvm based storage.
Prior to performing a restore of this nature the existing OS must be examined to capture
file system sizes and disk partition layouts.


This can be done by using the following commands:


        1. cat /etc/fstab

        2. cat /proc/partitions

        3. fdisk -l

        4. df

        5. lvm


                a) pvdisplay ← sub command within lvm

                b) vgdisplay

                c) lvdisplay


The following is the captured output from these commands run on a Linux system that
will be used to demonstrate this restore:


# cat /etc/fstab


        # This file is edited by fstab-sync - see 'man fstab-sync' for details
     /dev/VolGroup00/LogVol00 /
     ext3         defaults              1 1
     LABEL=/boot               /boot          ext3
     defaults              1 2
     none                      /dev/pts       devpts
     gid=5,mode=620        0 0
     none                      /dev/shm
     tmpfs        defaults              0 0
     none                      /proc          proc
     defaults              0 0
     none                      /sys
     sysfs        defaults              0 0
     /dev/VolGroup00/LogVol01 swap            swap
     defaults              0 0
     /dev/hda                  /media/cdrom   auto
     pamconsole,exec,noauto,managed   0 0
     /dev/fd0                  /media/floppy
     auto         pamconsole,exec,noauto,managed   0 0


# cat /proc/partitions


     major   minor       #blocks            name
         8      0        8388608             sda
         8      1         104391            sda1
         8      2        8281507            sda2
       253      0        6127616            dm-0
       253      1        2097152            dm-1


# 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
# df


        Filesystem                           1K-blocks
        Used      Available    Use%     Mounted on
        /dev/mapper/VolGroup00-LogVol00        6031296
        2829488        2895428      50%    /
        /dev/sda1                               101086
        10439          85428     11%     /boot
        none
        1027604             0        1027604      0%     /dev/shm


# lvm


        lvm>
        lvm> pvdisplay


              --- Physical volume ---
                  PV Name           /dev/sda2
                  VG Name           VolGroup00
                  PV Size           7.90 GB / not usable 23.41
              MB
                  Allocatable       yes
                  PE Size (KByte)   32768
                  Total PE          252
                  Free PE           1
                  Allocated PE      251
                  PV UUID           UK5qGM-55D1-I1aH-SsfA-
              n4pK-XRFW-mqJQke


        lvm> vgdisplay


              --- Volume group ---
                  VG Name                     VolGroup00
                  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 251 / 7.84
     GB
          Free PE               / Size 1 / 32.00
     MB
         VG UUID                BeC5YY-AFh9-W9Il-
     WwNH-38uj-Okd5-ETNkZh


lvm> lvdisplay


     --- Logical volume ---
         LV Name
     /dev/VolGroup00/LogVol00
         VG Name                VolGroup00
         LV UUID                Gx7TrH-mkIS-cJYq-
     kyVu-MeA6-BGrr-bMQqfL
         LV Write Access        read/write
         LV Status              available
         # open                 1
         LV Size                5.84 GB
         Current LE             187
         Segments               1
         Allocation             inherit
         Read ahead sectors     auto
         - currently set to     256
         Block device           253:0

     --- Logical volume ---
         LV Name
     /dev/VolGroup00/LogVol01
         VG Name                VolGroup00
         LV UUID                FaoqID-ns1A-bW48-
     2ZyB-xm1L-XH2k-85IuiQ
         LV Write Access        read/write
         LV Status              available
         # open                 1
         LV Size                2.00 GB
         Current LE             64
                       Segments                               1
                       Allocation                             inherit
                       Read ahead sectors                     auto
                       - currently set to                     256
                       Block device                           253:1


        lvm> exit




Resolution:
Once this information has been gathered, and a full backup has been run of the server, the
client is powered off, and the system disk is then replaced with a same sized disk. In
addition to that disk, another disk is also added to install a basic Linux OS which will be
used to restore the original disk. Be sure to replace the original system disk with the
same type of disk using the same target ID. Add the additional new disk to a different
SCSI ID from the original system disk. This will ensure that reconfiguring the restored
OS goes smoothly. On this system the original 8GB “sda” disk is replaced with another
“sda” disk (SCSI target 0), and a new 4GB sdb disk (SCSI target 1) is added. A bare
minimum Linux OS will be installed onto the sdb disk which will then get CommVault
Software FS agent installed on to it. At that point a restore will be performed, restoring
the data back on to sda (as it was originally installed).


From the output above it can be noted that the root “/” partition was located on
/dev/VolGroup00/LogVol00, a swap partition was located on
/dev/VolGroup00/LogVol01, and the “/boot” partition was located on a regular non lvm
/dev/sda1 partition. The VolGroup00 was located on disk partition /dev/sda2.

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1
posted:1/4/2013
language:English
pages:5