Linux/VM: Cloning Red Hat Linux Running in an LPAR

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Sunday, July 06, 2008

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Red Hat Linux LPAR Mode Cloning Process

Contributed by Mike W. Nettles, January 2007.

This HOWTO will show two different methods of cloning a Red Hat Linux system running in an LPAR. The first will use native Linux tools, and the second will use MVS tools.

The first scenario will use one Linux system (linux1) to copy a second Linux system (linux2) to yet a third Linux system (linux3). The Linux LPARs and their respective DASD volumes are:

linux1 - BB28
linux2 - BB29
linux3 - BB2A

On the linux1 system, create a mount point for BB2A
```
mkdir /mnt/bb2a
```
Shut down the linux2 and linux3 systems (if either are up).

On linux1, bring BB29 and BB2A online

chccwdev -e 0.0.BB29
chccwdev -e 0.0.BB2A

Figure out what device names were assigned to the volumes:
```
grep -i -E "bb2a|bb29" /proc/dasd/devices
```
For this example, we will assume that BB29 was /dev/dasdb, with a single partition of /dev/dasdb1, and BB2A was /dev/dasdc.
Format the target volume
```
dasdfmt -b 4096 -P -f /dev/dasdc
```
Verify the device address being formatted and reply "yes"
Create a partition on the target volume
```
fdasd -a /dev/dasdc
```
Strictly speaking, this step is not necessary, since the following steps will copy the partition table over along with all the other data. Still, it's not a bad practice to do it anyway.
Double check the DASD device names against addresses before copying
```
cat /proc/dasd/devices
```
Copy BB29 to BB2A
```
dd if=/dev/dasdb of=/dev/dasdc
```
Mount the target volume file system
```
mount /dev/dasdc1 /mnt/bb2a
```
If it mounts without any errors, the copy was very likely successful. Now we will modify the target volume so that it will be usable as linux3.
Update the file system label
```
e2label /dev/dasdc1 BB2A
```
Edit the following files
- /mnt/bb2a/etc/sysconfig/network
  - Change the HOSTNAME to linux3
- /mnt/bb2a/etc/sysconfig/network-scripts/ifcfg-eth0
  - Change the IP address
- /mnt/bb2a/etc/hosts
  - Change the hostname to linux3
  - Change the IP address
- /mnt/bb2a/etc/modprobe.conf
  - Change the "options dasd_mod dasd=" line to say dasd=bb2a
- /mnt/bb2a/etc/fstab
  - Change the root file system entry to use label BB2A
```
LABEL=BB2A     /     ext3     defaults     1  1
```

Rebuild the IPL text for the target volume

chroot /mnt/bb2a
mount -t proc proc /proc
mkinitrd -v /boot/initrd-bb2a-yymmdd-hhss.img $(uname -r)
     initrd-bb2a.img is the new initrd file name
vi /etc/zipl.conf
     Change ramdisk to use /boot/initrd-bb2a-yymmdd-hhss.img
     Change parameters to parameters="root=LABEL=BB2A"
zipl -x
     Rewrite the IPL text and turn off reply option at IPL
umount /proc
exit
     To get out of chroot
cd
     To undo earlier cd /mnt/bb2a

Unmount BB2A
```
umount /mnt/bb2a
```

Put BB29 and BB2A offline

chccwdev -d 0.0.BB29
chccwdev -d 0.0.BB2A

Boot the linux3 system
If all is OK, reboot the linux2 system

The second scenario presumes that all the DASD involved can be brought online to your MVS system. MVS tools will be used to copy the linux1 system to linux2. The Linux LPARs and their respective DASD volumes are:

linux1 - BB28
linux2 - BB29

Make sure that both linux1 and linux2 are shut down

Perform a concurrent DFDSS full volume backup of BB28

//DUMP1   EXEC PGM=ADRDSSU,REGION=4096K,TIME=1439
//******************************************************************
//**** ****
//**** MAKE SURE LINUX1 IS DOWN BEFORE STARTING CONCURRENT COPY ****
//**** ****
//******************************************************************
//SYSPRINT DD SYSOUT=*
//DD1  DD  UNIT=3390,VOL=SER=0XBB28,DISP=SHR
//TAPE DD DISP=(,CATLG,DELETE),LABEL=(1,SL,EXPDT=99000),
//   UNIT=TAPE,
//   VOL=(,,,20),  
//   DSN=SPFBLD.V0XBB28.D060923.REL1301
//SYSIN  DD  *
 DUMP FULL INDDNAME(DD1) - 
 OUTDDNAME(TAPE) - 
 CONCURRENT -
 WAIT(2,50) ALLEXCP
*/
//

Run a full volume restore to BB29

//RESTORE EXEC PGM=ADRDSSU,REGION=4000K,TIME=1439
/***********************************************************
//**** ****
//**** MAKE SURE LINUX2 IS DOWN BEFORE STARTING RESTORE ****
//**** ****
//**********************************************************
//SYSPRINT DD  SYSOUT=*
//DISK   DD    UNIT=3390,VOL=SER=0XBB29,DISP=OLD
//TAPE   DD    DSN=SPFBLD.V0XBB29.D060923.REL1301,DISP=SHR
//SYSIN  DD  *
 RESTORE FULL -
 INDD(TAPE) -
 OUTDD(DISK) -
 PURGE -
 CAN
*/
//

IPL linux1 from BB28
On the linux1 system, create a mount point for BB29
```
mkdir /mnt/bb29
```
Vary BB29 online to linux1
```
chccwdev -e 0.0.bb29
```
Figure out what device names were assigned to the volumes:
```
grep -i bb29 /proc/dasd/devices
```
For this example, we will assume that BB29 was /dev/dasdm, with a single partition of /dev/dasdm1.
Mount the target volume file system
```
mount /dev/dasdm1 /mnt/bb29
```
If it mounts without any errors, the copy was very likely successful. Now we will modify the target volume so that it will be usable as linux2.
Update the file system label
```
e2label /dev/dasdm1 BB29
```
Edit the following files
- /mnt/bb29/etc/sysconfig/network
  - Change the HOSTNAME to linux2
- /mnt/bb29/etc/sysconfig/network-scripts/ifcfg-eth0
  - Change the IP address
- /mnt/bb29/etc/hosts
  - Change the hostname to linux2
  - Change the IP address
- /mnt/bb29/etc/modprobe.conf
  - Change the "options dasd_mod dasd=" line to say dasd=bb29
- /mnt/bb29/etc/fstab
  - Change the root file system entry to use label BB29
```
LABEL=BB29     /     ext3     defaults     1  1
```

Rebuild the IPL text for the target volume

chroot /mnt/bb29
mount -t proc proc /proc
mkinitrd -v /boot/initrd-bb29-yymmdd-hhss.img $(uname -r)
     initrd-bb29-yymmdd-hhss.img is the new initrd file name
vi /etc/zipl.conf
     Change ramdisk to use /boot/initrd-bb29-yymmdd-hhss.img
     Change parameters to parameters="root=LABEL=BB29"
zipl -x
     Rewrite the IPL text and turn off reply option at IPL
umount /proc
exit
     To get out of chroot
cd
     To undo earlier cd /mnt/bb29

Unmount BB29
```
umount /mnt/bb29
```
Put BB29 offline
```
chccwdev -d 0.0.BB29
```
Boot the linux2 system

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