openSolaris 2008 - Migrating a Non-Global Zone to a Different Machine - System Administration Guide: Virtualization Using the Solaris Operating System

Migrating a Non-Global Zone to a Different Machine

Note that you can do a trial run of a zone migration before you actually move the zone to a different machine. For more information, see About Validating a Zone Migration Before the Migration Is Performed.

About Migrating a Zone

The zonecfg and zoneadm commands can be used to migrate an existing non-global zone from one system to another. The zone is halted and detached from its current host. The zonepath is moved to the target host, where it is attached.

The following requirements apply to zone migration:

The global zone on the target system must be running the same Solaris release as the original host.
To ensure that the zone will run properly, the target system must have the same or later versions of the following required operating system packages and patches as those installed on the original host.
- Packages that deliver files under an inherit-pkg-dir resource
- Packages where SUNW_PKG_ALLZONES=true
Other packages and patches, such as those for third-party products, can be different.
If the new host has later versions of the zone-dependent packages or their associated patches, using zoneadm attach with the -u option updates those packages within the zone to match the new host.
The host and target systems must have the same machine architecture.

To verify the Solaris release and the machine architecture, type:

#uname -m

The zoneadm detach process creates the information necessary to attach the zone on a different system. The zoneadm attach process verifies that the target machine has the correct configuration to host the zone.

Because there are several ways to make the zonepath available on the new host, the actual movement of the zonepath from one system to another is a manual process that is performed by the global administrator.

When attached to the new system, the zone is in the installed state.

How to Migrate A Non-Global Zone

You must be the global administrator in the global zone to perform this procedure.

Become superuser, or assume the Primary Administrator role.
To create the role and assign the role to a user, see Using the Solaris Management Tools With RBAC (Task Map) in System Administration Guide: Basic Administration.
Halt the zone to be migrated, my-zone in this procedure.
```
host1# zoneadm -z my-zone halt
```
Detach the zone.
```
host1# zoneadm -z my-zone detach
```
The detached zone is now in the configured state.
Move the zonepath for my-zone to the new host.
See How to Move the zonepath to a new Host for more information.

On the new host, configure the zone.

host2# zonecfg -z my-zone

You will see the following system message:

my-zone: No such zone configured
Use 'create' to begin configuring a new zone.

To create the zone my-zone on the new host, use the zonecfg command with the -a option and the zonepath on the new host.
```
zonecfg:my-zone> create -a /export/zones/my-zone
```

(Optional) View the configuration.

zonecfg:my-zone> info
zonename: my-zone
zonepath: /export/zones/my-zone
autoboot: false
pool:
inherit-pkg-dir:
         dir: /lib
inherit-pkg-dir:
         dir: /platform
inherit-pkg-dir:
         dir: /sbin
inherit-pkg-dir:
         dir: /usr
net:
         address: 192.168.0.90
         physical: bge0

Make any required adjustments to the configuration.
For example, the network physical device is different on the new host, or devices that are part of the configuration might have different names on the new host.
```
zonecfg:my-zone> select net physical=bge0
zonecfg:my-zone:net> set physical=e1000g0
zonecfg:my-zone:net> end
```

Commit the configuration and exit.

zonecfg:my-zone> commit
zonecfg:my-zone> exit

Attach the zone on the new host.
- Attach the zone with a validation check.
```
host2# zoneadm -z my-zone attach
```
  The system administrator is notified of required actions to be taken if either or both of the following conditions are present:
  - Required packages and patches are not present on the new machine.
  - The software levels are different between machines.
- Update a zone to match a host running later versions of the dependent packages upon attach.
```
host2# zoneadm -z my-zone attach -u
```
  Tip - If the source system is running an older version of the Solaris system, it might not generate a correct list of packages when the zone is detached. To ensure that the correct package list is generated on the destination, you can remove the SUNWdetached.xml file from the zonepath. Removing this file will cause a new package list to be generated by the destination system.
- Force the attach operation without performing the validation.
```
host2# zoneadm -z my-zone attach -F
```
  Caution - The -F option allows you to force the attach with no validation performed. This is useful in certain cases, such as in a clustered environment or for backup and restore operations, but it does require that the system be properly configured to host the zone. An incorrect configuration could result in undefined behavior later.

How to Move the `zonepath` to a new Host

There are many ways to create an archive of the zonepath. For example, you can use the cpio or pax commands described in the cpio(1)) and pax(1) man pages.

There are also several ways to transfer the archive to the new host. The mechanism used to transfer the zonepath from the source host to the destination depends on the local configuration. In some cases, such as a SAN, the zonepath data might not actually move. The SAN might simply be reconfigured so the zonepath is visible on the new host. In other cases, the zonepath might be written to tape, and the tape mailed to a new site.

For these reasons, this step is not automated. The system administrator must choose the most appropriate technique to move the zonepath to the new host.

Become superuser, or assume the Primary Administrator role.
To create the role and assign the role to a user, see Using the Solaris Management Tools With RBAC (Task Map) in System Administration Guide: Basic Administration.
Move the zonepath to the new host. You can use the method described in this procedure, or use another method of your choice.

Example 23-1 Archiving and Moving the zonepath Using the tar Command

Create a tar file of the zonepath on host1 and transfer it to host2 by using the sftp command.

host1# cd /export/zones
host1# tar cf my-zone.tar my-zone
host1# sftp host2
Connecting to host2...
Password:
sftp> cd /export/zones
sftp> put my-zone.tar
Uploading my-zone.tar to /export/zones/my-zone.tar
sftp> quit

On host2, unpack the tar file.

host2# cd /export/zones
host2# tar xf my-zone.tar

For more information, see sftp(1) and tar(1).

Troubleshooting

See Resolving Problems With a zoneadm attach Operation for troubleshooting information on the following:

Patches and packages are out of sync.
Operating system releases do not match.

Next Steps

If you have copied the data instead of reconfiguring a SAN, then the zonepath data will still be visible on the source host even though the zone is now in the configured state. You can either manually remove the zonepath from the source host after you have finished moving the data to the new host, or you can reattach the zone to the source host and use the zoneadm uninstall command to remove the zonepath.

About Validating a Zone Migration Before the Migration Is Performed

You can perform a trial run before the zone is moved to the new machine by using the “no execute” option,-n.

The zoneadm detach subcommand is used with the -n option to generate a manifest on a running zone without actually detaching the zone. The state of the zone on the originating system is not changed. The zone manifest is sent to stdout. The global administrator can direct this output to a file or pipe it to a remote command to be immediately validated on the target host. The zoneadm attach subcommand is used with the -n option to read this manifest and verify that the target machine has the correct configuration to host the zone without actually doing an attach.

The zone on the target system does not have to be configured on the new host before doing a trial-run attach.

How to Validate a Zone Migration Before the Migration Is Performed