Re: [Qemu-discuss] qemu-img convert stuck

[Nir Soffer]

On Sun, Apr 8, 2018 at 9:27 PM Benny Zlotnik <address@hidden> wrote:

> Hi,
>
> As part of copy operation initiated by rhev got stuck for more than a day
> and consumes plenty of CPU
> vdsm     13024  3117 99 Apr07 ?        1-06:58:43 /usr/bin/qemu-img convert
> -p -t none -T none -f qcow2
>
> /rhev/data-center/bb422fac-81c5-4fea-8782-3498bb5c8a59/26989331-2c39-4b34-a7ed-d7dd7703646c/images/597e12b6-19f5-45bd-868f-767600c7115e/62a5492e-e120-4c25-898e-9f5f5629853e
> -O raw /rhev/data-center/mnt/mantis-nfs-lif1.lab.eng.tlv2.redhat.com:
>
> _vol__service/26989331-2c39-4b34-a7ed-d7dd7703646c/images/9ece9408-9ca6-48cd-992a-6f590c710672/06d6d3c0-beb8-4b6b-ab00-56523df185da
>
> The target image appears to have no data yet:
> qemu-img info 06d6d3c0-beb8-4b6b-ab00-56523df185da"
> image: 06d6d3c0-beb8-4b6b-ab00-56523df185da
> file format: raw
> virtual size: 120G (128849018880 bytes)
> disk size: 0
>
> strace -p 13024 -tt -T -f shows only:
> ...
> 21:13:01.309382 ppoll([{fd=12, events=POLLIN|POLLERR|POLLHUP}], 1, {0, 0},
> NULL, 8) = 0 (Timeout) <0.000010>
> 21:13:01.309411 ppoll([{fd=12, events=POLLIN|POLLERR|POLLHUP}], 1, {0, 0},
> NULL, 8) = 0 (Timeout) <0.000009>
> 21:13:01.309440 ppoll([{fd=12, events=POLLIN|POLLERR|POLLHUP}], 1, {0, 0},
> NULL, 8) = 0 (Timeout) <0.000009>
> 21:13:01.309468 ppoll([{fd=12, events=POLLIN|POLLERR|POLLHUP}], 1, {0, 0},
> NULL, 8) = 0 (Timeout) <0.000010>
>
> version: qemu-img-rhev-2.9.0-16.el7_4.13.x86_64
>
> What could cause this? I'll provide any additional information needed
>

A backtrace may help, try:

gdb -p 13024 -batch -ex "thread apply all bt"

Also adding Kevin and qemu-block.

Nir