[pve-devel] [PATCH v2 storage 05/10] rbd plugin: implement volume import/export

[Fiona Ebner]

Am 18.12.24 um 16:33 schrieb DERUMIER, Alexandre via pve-devel:
>>> Am 18.12.24 um 15:20 schrieb Daniel Kral:
>>>> - When exporting with "pvesm export ...", the volume has the same
>> checksum as with "rbd export ..." with the size header prepended
> 
>>> Well, I totally missed the existence of "rbd export" in my hurry to
>>> get
>>> this working. Seems to be about 1.5 times faster than mapping+dd from
>>> some initial testing. Will use that in v3.
> 
> Hi, fiona, rbd export|import, this is the way, like zfs send|receive. 
> (with snapshot support too, with export-diff|import-diff)
> 

Saw that in the man page, and yes, would be the way to go for an 'rbd'
transport format with incremental support similar to 'zfs' :)

> I't really fast because, if I remember, it's use big block size and is 
> able to do parallelism. (can be tunned with --rbd-concurrent-
> management-ops <number> )
> 

We'll need to evaluate trade-off between speed and putting more load on
the system/Ceph. After all, the disk move might not be the most
important thing happening at that moment.

> No related, but could it be possible to implement it, for simple
> vm/template full cloning with source+target are both rbd ? It's really
> faster with 'qemu-img convert'

Hmm, we could shift offline copy of images to the storage layer (at
least in some cases). We just need a version of storage_migrate() that
goes to the local node instead of SSH to a different one. Could you
please open a feature request for this?