[pve-devel] [PATCH v5 qemu-server 0/3] remote-migration: migration with different cpu

DERUMIER, Alexandre alexandre.derumier at groupe-cyllene.com
Fri Nov 17 09:52:09 CET 2023


Any chance to have it one merged for 8.1 ?

-------- Message initial --------
De: Alexandre Derumier <aderumier at odiso.com>
Répondre à: Proxmox VE development discussion <pve-
devel at lists.proxmox.com>
À: pve-devel at lists.proxmox.com
Objet: [pve-devel] [PATCH v5 qemu-server 0/3] remote-migration:
migration with different cpu
Date: 26/10/2023 10:57:07

This patch series allow remote migration between cluster with different
cpu model.

2 new params are introduced: "target-cpu" && "restart"

If target-cpu is defined, this will replace the cpu model of the target

If vm is online/running, an extra "target-reboot" safeguard option is
Indeed, as the target cpu is different, the live migration with memory
is skipped (as anyway, the target will die with a different cpu).

Then, after the storage copy, we switch source vm disk to the targetvm
nbd export,
then shutdown the source vm and restart the target vm.
(Like a virtual reboot between source/target)

We have redone a lot of migration this summer( maybe another 4000vm),
0 corruption, windows or linux guest vms.

Changelog v2:

The first version was simply shuting down the target vm,
wihout doing the block-job-complete.

After doing production migration with around 400vms, I had
some fs corruption, like some datas was still in buffer.

This v2 has been tested with another 400vms batch, without
any corruption.

Changelog v3:

v2 was not perfect, still have some 1 or 2 fs corruption with vms doing
a lot of write.

This v3 retake idea of the v1 but in a cleaner way

- we migrate disk to target vm
- source vm is switching disk to the nbd of the target vm.
  (with a block-job-complete, and not a block-job-cancel with standard
disk migration).
  We are 100% sure it that no pending write is still pending in the
migration job.
- source vm is shutdown
- target with is restart

Changelog v4:
 - bugfix: no not override cpu with empty config if targetcpu is not
 - small cleanups with params

Changelov V5:
 - Fix fiona comments
 - use "restart" param instead "target-reboot"
 - split target-cpu param in separated patch

Alexandre Derumier (3):
  migration: move livemigration code in a dedicated sub
  remote-migration: add restart param
  add target-cpu param

 PVE/API2/Qemu.pm   |  26 +++
 PVE/CLI/qm.pm      |  12 ++
 PVE/QemuMigrate.pm | 452 ++++++++++++++++++++++++---------------------
 3 files changed, 281 insertions(+), 209 deletions(-)

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