6.18 Moving a Guest to a Different Database Server

Guests can move to different database servers.

The target Oracle Exadata database server must meet the following requirements:

• The target database server must have the same Oracle Exadata System Software release installed with Oracle Linux KVM.

• The target database server must have the same network visibility.

• The target database server must have access to the same Oracle Exadata storage servers.

• The target database server must have sufficient free resources (CPU, memory, and local disk storage) to operate the guest.

  • It is possible to over-commit virtual CPUs such that the total number of virtual CPUs assigned to all domains exceeds the number of physical CPUs on the system. Over-committing CPUs can be done only when the competing workloads for over-subscribed resources are well understood and the concurrent demand does not exceed physical capacity.

  • It is not possible to over-commit memory.

  • Copying disk images to the target database server may increase space allocation of the disk image files because the copied files are no longer able to benefit from the disk space savings gained by using reflinks.

• The guest name must not be already in use on the target database server.

The following procedure moves a guest to a new database server in the same Oracle Exadata System Software configuration.

1. In the KVM host, shut down the guest that is being moved.

   # vm_maker --stop-domain GuestName

2. Copy the guest disk image and configuration files to the target database server.

   In the following examples, replace GuestName with the name of the guest, and replace target with the host name of the target KVM host.

   # scp -r /EXAVMIMAGES/GuestImages/GuestName/ target:/EXAVMIMAGES/GuestImages

3. Copy the guest XML definition to the target database server.

   # scp /etc/libvirt/qemu/GuestName.xml target:/EXAVMIMAGES/GuestImages

4. In the target KVM host, define the domain.

   # virsh define /EXAVMIMAGES/GuestImages/GuestName.xml

5. If you are using Oracle Exadata System Software release 20.1 or later, run the following vm_maker command in the target KVM host to complete the guest migration.

   # vm_maker --update-mac GuestName

   Note:

   • The vm_maker --update-mac command is first introduced in Oracle Exadata System Software release 20.1.4 (November 2020). If you are using an earlier 20.1 release, you must perform an update to get this command.

   • This step is not required on systems using a release of Oracle Exadata System Software prior to 20.1.

6. Start the migrated guest on the target KVM host.

   # vm_maker --start-domain GuestName