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

[Alexandre DERUMIER]

>>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.
Yes sure!

I'm currently looking at qemu code to see how nbd client works.

----- Mail original -----
De: "Wolfgang Bumiller" <w.bumiller at proxmox.com>
À: "aderumier" <aderumier at odiso.com>
Cc: "pve-devel" <pve-devel at pve.proxmox.com>, "dietmar" <dietmar at proxmox.com>
Envoyé: Mercredi 21 Décembre 2016 12:20:28
Objet: Re: [pve-devel] [PATCH 2/6] qemu_drive_mirror : handle multiple jobs

> 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.