@migration snapshots left over


on my LXD there are some snapshots in the ZFS pool with @migration suffix . What are these snapshots are for ? They do not exist for every container but some of them. e.g.

VIRT-MASTER:~ root @ zfs list -t all | grep migration
dpool/lxd/containers/archive@migration-abcf98c1-d1bb-4144-9cad-66989bd4db88                          312K      -  2.41G  -                                                                                                                 
dpool/lxd/containers/archive@migration-350b94a5-d795-4302-82e8-0fa66eeb5485                          313K      -  2.41G  -                                                                                                                 
dpool/lxd/containers/archive@migration-2ac8ae01-1d83-4412-b065-d3a0933a75ab                          431K      -  2.32G  -                                                                                                                 
dpool/lxd/containers/archive@migration-60358e05-239a-4582-be8b-356e6fd6bcc3                          431K      -  2.32G  -                                                                                                                 
dpool/lxd/containers/darwin@migration-bdfd8690-798f-4da6-910a-0a8e4f7a44ec                          1.25M      -  3.41G  -                                                                                                                 
dpool/lxd/containers/darwin@migration-fc1dc522-b6e3-475f-8868-a23d23f1776c                          1.25M      -  3.41G  -                                                                                                                 
dpool/lxd/containers/darwin@migration-517ec125-fce8-4519-9f14-7f93a32172d0                          1.26M      -  3.40G  -                                                                                                                 
dpool/lxd/containers/darwin@migration-610bbfba-6411-489b-87b8-3eca6f0cafa2                          1.26M      -  3.40G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-c1819d42-5656-4e2a-98f0-0f177bc1271c                         752M      -  9.06G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-e00aeec0-c2af-41ab-a4d5-e028001cd48d                         752M      -  9.06G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-01396c8b-4c19-4d76-9e03-237a1efe0d48                         789M      -  9.21G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-74a77423-0c5b-4e79-82e2-219fa1fcd749                         789M      -  9.21G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-9748f7ab-726b-4533-be2b-a51638c3932f                        11.5M      -  9.41G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-6e825bdf-cae7-48d4-b9e6-a6cf650dc36a                        11.5M      -  9.41G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-c4e2e3c5-6267-4a09-a1ba-6cedf581cab7                        3.00M      -  9.43G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-0c1941dd-5777-4acb-85dd-92af49e2ba58                        3.00M      -  9.43G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-90b36250-90af-4256-9fd9-0f5d0e86b1a5                        47.1M      -  9.50G  -                                                                                                                 
dpool/lxd/containers/librenms@migration-196b6d55-7572-4ffc-850f-fb8ad8c115ee                        47.5M      -  9.50G  -                                                                                                                 
dpool/lxd/containers/mx1@migration-97db9fa0-d986-4483-a6e0-a03be54ccefb                              800K      -  2.48G  -                                                                                                                 
dpool/lxd/containers/mx1@migration-a12f8281-c1b8-40b4-b8db-dd9c46e8e24e                              796K      -  2.48G  -                                                                                                                 
dpool/lxd/containers/mx1@migration-460a8cfd-cfff-4150-8a23-a53f1242a635                              103M      -  2.49G  -                                                                                                                 
dpool/lxd/containers/mx1@migration-5e15b618-dbc9-4e74-b148-434e9990b4f6                              103M      -  2.49G  

I can also find sometimes a process that seems not to end:

8974 ? S 0:00 zfs send -c -L -i dpool/lxd/containers/librenms@migration-90b36250-90af-4256-9fd9-0f5d0e86b1a5 dpool/lxd/containers/librenms@migration-196b6d55-7572-4ffc-850f-fb8ad8c115ee

I sync every night with lxc delete and lxc copy to another host.

They’re safe to delete, they should just be there temporarily during a send/receive operation. They may have been left over in your case due to a crash or other issue during the migration.

The same may be true of that zfs send process which may hint at a network issue or something else causing the migration to fail partway through.

Thanks for the reply. I’ve deleted the snapshot without problems. I’ll have to investigate this but it seems uncommon that this a network problem because the two machines are connected directly over 100Gbit LAN.