Cloning partition on IBM VIO server

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Cloning virtual disk or network installation?

Usually network installation will be a better way to deploy a new LPAR. Using network installation server and automated installation environment you will install AIX, SUSE or Red Hat base operating system in less then 10 minutes. Cloning LPAR can be used for deploying more software and all the post installation customization. It also can be used for keeping a snapshot of the system before making any changes or upgrading to the next release. With the copy of your virtual disk you can go back in minutes and boot it. There are some things to consider before you are going to clone the exported logical volume: if you are cloning AIX set your IP to some dummy address or remove your IP configuration. For Linux this is not necessary, as Red Hat and SUSE assign the configured IP according to the MAC of the NIC. You will also need to change the hostname of the cloned system. In the DLPAR environment you may need to reconfigure your RSCT Daemons as they need unique identifiers on all LPARs. On Linux this can be achieved through following command:

/usr/sbin/rsct/install/bin/recfgct

Copy your virtual disk

Login to your VIO server as user "padmin". Check your exported logical volumes:

  • List volume groups:
 $ lsvg
rootvg
datavg
  • List logical volumes in your datavg
 $ lsvg -lv datavg
datavg:
LV NAME             TYPE       LPs   PPs   PVs  LV STATE      MOUNT POINT
vdisk0              jfs        272   272   1    open/syncd    N/A
vdisk1              jfs        272   272   1    open/syncd    N/A
vdisk2              jfs        272   272   1    open/syncd    N/A
vdisk3              jfs        272   272   1    open/syncd    N/A
vdisk4              jfs        272   272   1    open/syncd    N/A
  • Check the mapping of the virtual device
 $ lsmap -vadapter vhost1
SVSA            Physloc                                      Client Partition ID
vhost1          U9123.710.1008B2A-V1-C4                      0x00000000
VTD                   vtscsi1
LUN                   0x8100000000000000
Backing device        vdisk1
Physloc
  • Create a target logical volume:
 mklv -lv vdisk1clone datavg 17G
  • Shutdown your source LPAR (recommended)
  • Become root on VIO
$ oem_setup_env

  • List the device (this is a virtual disk, exported logical volume, do not confuse it with hdisk1 which is a second physical disk)
# ls -al /dev/*vdisk1
 crw-rw----   1 root     staff        36,  2 Oct 18 15:31 /dev/rvdisk1
 brw-rw----   1 root     staff        36,  2 Oct 18 15:31 /dev/vdisk1
  • Clone it:

For cloning we will use the raw device starting with "r" /dev/rvdisk1, cloning buffered device with dd takes longer. We will also use 8MB block size, which significantly increases the cloning speed.

# time dd if=/dev/rvdisk1 of=/dev/rvdisk1clone bs=8M 

It took 5 minutes to copy 17 GB disk (compared to 40 minutes using cplv command)

See also the diskussion at http://www-128.ibm.com/developerworks/forums/dw_thread.jsp?forum=748

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