(Optional) Perform Post-BMR Operations

The following topics are optional configuration settings that you may have to perform after a BMR:

Configure X Windows

When you perform a BMR across a dissimilar hardware, X Windows of the restored OS does not function properly and the target node displays an error dialog. The error dialog appears because the display configuration has changed. To resolve this error, follow the instructions in the error dialog to configure the graphic card. After that, you can see the X Windows and the desktop UI.

Configure the System Fully Qualified Domain Name (FQDN)

When you need an FQDN, then you must configure the FQDN. The BMR process does not automatically configure the FQDN.

Maximum character count for FQDN: 63

Follow these steps to configure the FQDN:

Edit the /etc/hosts file and provide the IP Address, the FQDN name, and the server name.

#vi /etc/hosts

ip_of_system servername.domainname.com servername

Restart the network service.

#/etc/init.d/network restart

Verify the host name and the FQDN name.

#hostname

servername

#hostname -f

servername.domainname.com

The FQDN is configured.

Extend the Data Volume after a BMR on Dissimilar Disks

When you perform a BMR to a larger disk than the disk on the original node, some disk space is left unused. The BMR operation does not automatically process the unused disk space. You can format the disk space to a separate partition or resize the existed partition with the unused disk space. The volume that you want to resize must be unused, so you must avoid resizing a system volume. In this section, we will focus on how to extend a data volume with the unused disk space.

Note: To avoid data loss, resize your volumes immediately after the BMR process. You can also back up the node before starting the volume resizing task.

When the target machine successfully restarts after the BMR, you can extend the data volume.

Raw partition volume

For example, a 2-GB disk in the session is restored to a 16-GB disk named /dev/sdb with only one partition. The /dev/sdb1 raw partition is directly mounted on the /data directory.

This example is used to explain the procedure of extending Raw partition volume.

Follow these steps:

Check the status of the /dev/sdb1 volume.

# df –h /dev/sdb1

/dev/sdb1 2.0G 40M 1.9G 3% /data

Umount the /dev/sdb1 volume.

# umount /data

Resize /dev/sdb1 to occupy the entire disk space using the fdisk command.

To perform this operation, first delete your existing partition and then recreate it with the same start sector number. The same start sector number is responsible for avoiding the data loss.

# fdisk -u /dev/sdb

Command (m for help): p

Disk /dev/sdb: 17.1 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders, total 33554432 sectors

Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System

/dev/sdb1 63 4192964 2096451 83 Linux

Command (m for help): d

Selected partition 1

Command (m for help): n

Command action

e extended

p primary partition (1-4)

Partition number (1-4): 1

First sector (63-33554431, default 63):

Using default value 63

Last sector or +size or +sizeM or +sizeK (63-33554431, default 33554431):

Using default value 33554431

Command (m for help): p

Disk /dev/sdb: 17.1 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders, total 33554432 sectors

Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System

/dev/sdb1 63 33554431 16777184+ 83 Linux

Command (m for help): w

The partition changes to the same start sector number as the original partition and the end sector number is 33554431.

Resize the volume using resize2fs command. If necessary, first run the e2fsck command.

# e2fsck -f /dev/sdb1

# resize2fs /dev/sdb1

Mount the volume to the mount point and check the volume status again.

# mount /dev/sdb1 /data

# df –h /dev/sdb1

/dev/sdb1 16G 43M 16G 1% /data

The volume is extended to 16 GB and is ready for use.

LVM volume:

For example, an 8-GB disk in the session is restored to a 16-GB disk named /dev/sdc with only one partition. The /dev/sdc1 raw partition is used as the only physical volume of the /dev/mapper/VGTest-LVTest LVM logical volume whose mount point is /lvm.

This example is used to explain the procedure of extending LVM volume.

Follow these steps:

Check the status of the /dev/mapper/VGTest-LVTest volume.

# lvdisplay –m /dev/mapper/VGTest-LVTest

--- Logical volume ---

LV Name /dev/VGTest/LVTest

VG Name VGTest

LV UUID udoBIx-XKBS-1Wky-3FVQ-mxMf-FayO-tpfPl8

LV Write Access read/write

LV Status available

# open 1

LV Size 7.88 GB

Current LE 2018

Segments 1

Allocation inherit

Read ahead sectors 0

Block device 253:2

---Segments---

Logical extent 0 to 2017:

Type linear

Physical volume /dev/sdc1

Physical extents 0 to 2017

The physical volume is /dev/sdc1, the volume group is VGTest, and the logical volume is /dev/VGTest/LVTest or /dev/mapper/VGTest-LVTest.

Umount the /dev/mapper/VGTest-LVTest volume.

# umount /lvm

Disable the volume group in which the /dev/sdc1 physical volume is located.

# vgchange -a n VGTest

Create a partition to occupy the unused disk space using the fdisk command.

# fdisk -u /dev/sdc

Command (m for help): p

Disk /dev/sdc: 17.1 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders, total 33554432 sectors

Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System

/dev/sdc1 63 16777215 8388576+ 83 Linux

Command (m for help): n

Command action

e extended

p primary partition (1-4)

Partition number (1-4): 2

First sector (16777216-33554431, default 16777216):

Using default value 16777216

Last sector or +size or +sizeM or +sizeK (16777216-33554431, default 33554431):

Using default value 33554431

Command (m for help): p

Disk /dev/sdc: 17.1 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders, total 33554432 sectors

Units = sectors of 1 * 512 = 512 bytes

Device Boot Start End Blocks Id System

/dev/sdc1 63 16777215 8388576+ 83 Linux

/dev/sdc2 16777216 33554431 8388608 83 Linux

Command (m for help): w

The /dev/sdc2 partition is created.

Create a new physical volume.

# pvcreate /dev/sdc2

Extend the volume group size.

# vgextend VGTest /dev/sdc2

Enable the volume group that you have already disabled.

# vgchange -a y VGTest

Extend the logical volume size using the lvextend command.

# lvextend -L +8G /dev/VGTest/LVTest

Resize the volume using the resize2fs command. If necessary, first run the e2fsck command.

# e2fsck -f /dev/mapper/VGTest-LVTest

# resize2fs /dev/mapper/VGTest-LVTest

Mount the volume to the mount point and check the volume status again.

# mount /dev/mapper/VGTest-LVTest /lvm

# lvdisplay -m /dev/mapper/VGTest-LVTest

---Logical volume---

LV Name /dev/VGTest/LVTest

VG Name VGTest

LV UUID GTP0a1-kUL7-WUL8-bpbM-9eTR-SVzl-WgA11h

LV Write Access read/write

LV Status available

# open 0

LV Size 15.88 GB

Current LE 4066

Segments 2

Allocation inherit

Read ahead sectors 0

Block device 253:2

--- Segments ---

Logical extent 0 to 2046:

Type linear

Physical volume /dev/sdc1

Physical extents 0 to 2046

Logical extent 2047 to 4065:

Type linear

Physical volume /dev/sdc2

Physical extents 0 to 2018

The LVM volume extends to 16 GB and is ready for use.