[pve-devel] [PATCH 2/6] qemu_drive_mirror : handle multiple jobs

[Wolfgang Bumiller]

> On December 21, 2016 at 10:51 AM Alexandre DERUMIER <aderumier at odiso.com> wrote:
> 
> 
> >>IIRC that was the only blocker.
> >>
> >>Basically the patchset has to work *without* tcp_ping() since it is an
> >>unreliable check, and then we still have to catch failing connections
> >>_correctly_. (There's no point in knowing that "some time in the past
> >>you were able to connect to something which may or may not have been a
> >>qemu nbd server", we need to know whether the drive-mirror job itself
> >>was able to connect.)
> 
> For me, the mirror job auto abort if connection is failing during the migration. Do you see another behaviour ?

That covers one problem. IIRC the disk-deletion problem was that due
to wrong [] usage around an ipv6 address it could not connect in the
first place and didn't error as I would have hoped.

> 
> the tcp_ping was just before launching the drive mirror command, because it was hanging in this case.

Then it can still hang if the destination disappears between tcp_ping()
and the `drive-mirror` command, so I'd rather get better behavior on qemu's
side. It needs a time-out or a way to cancel it or something.