Hi,
I tried to implement a Quick Migration using ZFS snapshot/send/receive. It works, but not as fast as I would like. Migration of the server with 1 GB of RAM takes about 1 minute. Almost all of the time is spent on saving, copying and restoring the state of VM.
Here is an example of commands and spent time on their implementation.
Question: Is it possible to implement a similar replication in Live Migration process in the following scenario?
1. Create a running VM disk snapshot and replicate it to another cluster node
2. Run the migration process: the memory of a running VM is copied to another cluster node
3. Switch the VM into "Suspended" state
4. Create a running VM disk snapshot again and copy it to another cluster node
5. Move the configuration of the VM to another cluster node
6. Resume the VM on the new cluster node
7. Remove unnecessary snapshots on the both nodes
I tried to implement a Quick Migration using ZFS snapshot/send/receive. It works, but not as fast as I would like. Migration of the server with 1 GB of RAM takes about 1 minute. Almost all of the time is spent on saving, copying and restoring the state of VM.
Here is an example of commands and spent time on their implementation.
Code:
2015-03-18 10:01:10 0 qm suspend 100
2015-03-18 10:01:10 8 qm snapshot 100 s5 -vmstate
2015-03-18 10:01:18 1 zfs send -i rpool/vm-100-disk-1@s4 rpool/vm-100-disk-1@s5 | ssh vmc1-1 "zfs recv rpool/vm-100-disk-1"
2015-03-18 10:01:19 0 zfs snapshot rpool/vm-100-state-s5@s
2015-03-18 10:01:19 31 zfs send rpool/vm-100-state-s5@s | ssh vmc1-1 "zfs recv rpool/vm-100-state-s5"
2015-03-18 10:01:50 0 zfs destroy rpool/vm-100-state-s5@s
2015-03-18 10:01:50 0 ssh vmc1-1 "zfs destroy rpool/vm-100-state-s5@s"
2015-03-18 10:01:50 1 qm stop 100
2015-03-18 10:01:51 0 mv /etc/pve/nodes/vmc1-2/qemu-server/100.conf /etc/pve/nodes/vmc1-1/qemu-server/
2015-03-18 10:01:51 12 ssh vmc1-1 "qm rollback 100 s5"
2015-03-18 10:02:03 = 53 sec
Code:
# zfs list -t all
NAME USED AVAIL REFER MOUNTPOINT
rpool 54.4G 219G 144K /rpool
rpool/ROOT 6.76G 219G 144K /rpool/ROOT
rpool/ROOT/pve-1 6.76G 219G 6.76G /
rpool/swap 37.1G 256G 76K -
rpool/vm-100-disk-1 4.39G 219G 3.82G -
rpool/vm-100-disk-1@s1 295M - 3.49G -
rpool/vm-100-disk-1@s2 235M - 3.68G -
rpool/vm-100-disk-1@s3 1.26M - 3.82G -
rpool/vm-100-disk-1@s4 708K - 3.82G -
rpool/vm-100-disk-1@s5 0 - 3.82G -
rpool/vm-100-state-s1 1001M 219G 1001M -
rpool/vm-100-state-s2 1.22G 219G 1.22G -
rpool/vm-100-state-s3 1.25G 219G 1.25G -
rpool/vm-100-state-s4 1.25G 219G 1.25G -
rpool/vm-100-state-s5 1.25G 219G 1.25G -1. Create a running VM disk snapshot and replicate it to another cluster node
2. Run the migration process: the memory of a running VM is copied to another cluster node
3. Switch the VM into "Suspended" state
4. Create a running VM disk snapshot again and copy it to another cluster node
5. Move the configuration of the VM to another cluster node
6. Resume the VM on the new cluster node
7. Remove unnecessary snapshots on the both nodes
