Re: [Qemu-devel] drive-mirroring to nbd is failing with multiple parallel jobs (qemu 2.9 -> 2.11)

[Alexandre DERUMIER]

Sorry, I just find that the problem is in our proxmox implementation,

as we use a socat tunnel for the nbd mirroring, with a timeout of 30s in case 
of inactivity.

So, not a qemu bug.

Regards,

Alexandre

----- Mail original -----
De: "aderumier" <address@hidden>
À: "qemu-devel" <address@hidden>
Envoyé: Mercredi 14 Février 2018 09:54:21
Objet: [Qemu-devel] drive-mirroring to nbd is failing with multiple parallel 
jobs (qemu 2.9 -> 2.11)

Hi, 

I currently have failing mirroring jobs to nbd, when multiple jobs are running 
in parallel. 


step to reproduce, with 2 disks: 


1) launch mirroring job of first disk to remote target nbd.(to qemu running 
target) 
2) wait until is reach ready = 1 , do not complete 
3) launch mirroring job of second disk to remote target nbd(to same qemu 
running target) 

-> mirroring job of second disk is currently running (ready=0), first disk is 
still at ready=1 and still mirroring new write coming. 


then, after some time, mainly if no new write are coming to first disk (around 
30-40s), the first job is crashing with input/output error. 



Note that I don't have network problem, or disk problem, I'm able to mirror 
both disk individually. 


Another similar bug report on proxmox bugzilla: 

https://bugzilla.proxmox.com/show_bug.cgi?id=1664 


Maybe related to this : 
https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg03086.html 
? 


I don't remember to have the problem with qemu 2.7, but I'm able to reproduce 
with qemu 2.9 && qemu 2.11. 


Best Regards, 

Alexandre