How to migrate virtual servers between different data centers that do not share the same SAN?
There are limitations, including connection technology, depending on the Storage Model used.
For example, Dell PowerStore uses only 1 iSCSI network and Dell EMC Compellent, 2 separate iSCSI networks.
This connection is not possible, even for security and redundancy reasons.
Exports Domains are marked as discontinued in 4.4.x.
Export domain is deprecated, but it is still available
Are there plans for 4.4.x or 4.5.x Live Migrate Storage to be implemented?
I don't know about plans for live migration, but offline migration is available
since 3.6 by detaching the storage domain from one DC, and attaching it
to another DC (or completely separate setup).
I'm not sure why networking should be an issue.
This is the most efficient way because no data is copied, but it works only if
you want to move the entire storage domain from one DC to another. If you
want to move only a few VMs, you can export the VM to OVA and import the
OVA on the other DC.
Another way, which may require more work but can be faster is to
download the vm disks and upload them to the other storage.
Example - downloding disk from one DC/system:
# python3 /usr/share/doc/python3-ovirt-engine-sdk4/examples/upload_disk.py \
-c engine --disk-format=qcow2 --disk-sparse --sd-name fc_0 disk1.qcow2
And uploading to another DC/system, using different format:
# python3 /usr/share/doc/python3-ovirt-engine-sdk4/examples/upload_disk.py \
-c engine --disk-format=raw --disk-sparse --sd-name nfs_0 disk1.qcow2
This works for powered off VM. If you want move a running VM, it is possible to use
the backup_vm.py example to download all the disk of a running VM. Then you
can upload them to another system and create a VM from the disks.
Here is an example backup downloading all the 9 disks of a running vm:
# python3 /usr/share/doc/python3-ovirt-engine-sdk4/examples/backup_vm.py -c engine full --backup-dir /dev/shm/my-backup 20c83016-4c95-42d1-8aec-f75bdf62f471
[ 0.0 ] Starting full backup for VM 20c83016-4c95-42d1-8aec-f75bdf62f471
[ 1.9 ] Waiting until backup b9125cb5-c2eb-4f1e-953e-c2b8d5065996 is ready
[ 34.4 ] Created checkpoint '222a88f7-14f2-46e5-a3aa-b618c79a6445' (to use in --from-checkpoint-uuid for the next incremental backup)
[ 34.5 ] Creating image transfer for disk d6e3cca3-ca73-4169-b76e-f9928e727f9b
[ 35.7 ] Image transfer d360c489-2fdb-4f4c-9d32-4bdb7d83a948 is ready
[ 100.00% ] 3.00 GiB, 0.07 seconds, 43.54 GiB/s
[ 35.7 ] Finalizing image transfer
[ 37.8 ] Creating image transfer for disk f7fec022-dd6d-4170-b0f1-cab3bfa59e52
[ 39.0 ] Image transfer ba3fc564-2d88-4cc6-a0e7-220b132082ed is ready
[ 100.00% ] 1.00 GiB, 1.41 seconds, 726.56 MiB/s
[ 40.4 ] Finalizing image transfer
[ 44.5 ] Creating image transfer for disk 6797a952-6219-4baf-9b37-c7905b3e8431
[ 45.7 ] Image transfer 3b8e5bf6-bc95-4d3e-bc76-a169f44259df is ready
[ 100.00% ] 2.00 GiB, 0.06 seconds, 34.33 GiB/s
[ 45.7 ] Finalizing image transfer
[ 47.8 ] Creating image transfer for disk e57e7263-3683-4e7e-8f91-1b3d2784ba7f
[ 49.0 ] Image transfer 9dca0ce2-bcae-45f9-8372-5c3444392e06 is ready
[ 100.00% ] 1.00 GiB, 1.49 seconds, 686.21 MiB/s
[ 50.5 ] Finalizing image transfer
[ 51.5 ] Creating image transfer for disk def1bf0b-f4bb-4c55-acad-3407b4fa51a3
[ 52.7 ] Image transfer 9420754f-26ae-463e-9b4b-8d16bbc639bf is ready
[ 100.00% ] 1.00 GiB, 1.49 seconds, 689.46 MiB/s
[ 54.2 ] Finalizing image transfer
[ 58.3 ] Creating image transfer for disk 505a9363-d7b0-4a31-ab24-a02157d5da0a
[ 59.4 ] Image transfer 82cb3e00-cedb-486e-b0a7-938b7ad85ddf is ready
[ 100.00% ] 3.00 GiB, 0.06 seconds, 49.46 GiB/s
[ 59.5 ] Finalizing image transfer
[ 61.5 ] Creating image transfer for disk 29943aa5-2ffc-408e-950b-a2f6ded72f89
[ 62.7 ] Image transfer fa9bc0dc-5167-4b3c-adc5-394cfb3c3b76 is ready
[ 100.00% ] 3.00 GiB, 0.06 seconds, 51.15 GiB/s
[ 62.7 ] Finalizing image transfer
[ 64.8 ] Creating image transfer for disk 524cff40-3f54-4d16-bd94-9902e6619190
[ 65.9 ] Image transfer 7d053497-3830-4548-a9fb-d75f7b816dde is ready
[ 100.00% ] 10.00 GiB, 3.36 seconds, 2.98 GiB/s
[ 69.3 ] Finalizing image transfer
[ 72.4 ] Creating image transfer for disk ff71c7d3-5af3-4943-b922-b5baeb0be67c
[ 73.5 ] Image transfer 5cb9efb9-537c-4e16-b9b3-44ef44ab59dd is ready
[ 100.00% ] 2.00 GiB, 0.06 seconds, 33.31 GiB/s
[ 73.5 ] Finalizing image transfer
[ 74.6 ] Creating image transfer for disk b49df79e-7b26-402b-bf11-328fddeca1ec
[ 75.7 ] Image transfer 3ccc44f2-ba6d-4545-bc96-1b924b2c1dd8 is ready
[ 100.00% ] 2.00 GiB, 0.10 seconds, 20.20 GiB/s
[ 75.8 ] Finalizing image transfer
[ 77.9 ] Finalizing backup
[ 78.0 ] Waiting until backup is finalized
[ 78.2 ] Full backup completed successfully
# ls -lhs /dev/shm/my-backup/
total 5.4G
196K -rw-r--r--. 1 root root 193K Mar 16 22:58 29943aa5-2ffc-408e-950b-a2f6ded72f89.202103162258.full.qcow2
196K -rw-r--r--. 1 root root 193K Mar 16 22:58 505a9363-d7b0-4a31-ab24-a02157d5da0a.202103162258.full.qcow2
2.4G -rw-r--r--. 1 root root 2.4G Mar 16 22:59 524cff40-3f54-4d16-bd94-9902e6619190.202103162258.full.qcow2
196K -rw-r--r--. 1 root root 193K Mar 16 22:58 6797a952-6219-4baf-9b37-c7905b3e8431.202103162258.full.qcow2
196K -rw-r--r--. 1 root root 193K Mar 16 22:59 b49df79e-7b26-402b-bf11-328fddeca1ec.202103162258.full.qcow2
196K -rw-r--r--. 1 root root 193K Mar 16 22:58 d6e3cca3-ca73-4169-b76e-f9928e727f9b.202103162258.full.qcow2
1.1G -rw-r--r--. 1 root root 1.1G Mar 16 22:58 def1bf0b-f4bb-4c55-acad-3407b4fa51a3.202103162258.full.qcow2
1.1G -rw-r--r--. 1 root root 1.1G Mar 16 22:58 e57e7263-3683-4e7e-8f91-1b3d2784ba7f.202103162258.full.qcow2
1.1G -rw-r--r--. 1 root root 1.1G Mar 16 22:58 f7fec022-dd6d-4170-b0f1-cab3bfa59e52.202103162258.full.qcow2
196K -rw-r--r--. 1 root root 193K Mar 16 22:59 ff71c7d3-5af3-4943-b922-b5baeb0be67c.202103162258.full.qcow2
With some more work, one can build semi-live migration using backup
and upload.
Nir