[Libguestfs] Virt-v2v conversion issue
AVONDRA at unicef.fr
Wed Oct 15 13:49:55 UTC 2014
Killall does nothing the process is still alive...
If I do kill -9, do I get a core dump ?
Each time I got this hang, I find only umount -f /tmp/xxxx to force qemu-img to stop.
De : Richard W.M. Jones [mailto:rjones at redhat.com]
Envoyé : mercredi 15 octobre 2014 14:41
À : VONDRA Alain
Cc : libguestfs at redhat.com
Objet : Re: [Libguestfs] Virt-v2v conversion issue
On Wed, Oct 15, 2014 at 12:23:17PM +0000, VONDRA Alain wrote:
> Now, the conversion hangs on the first disk at 54,03/100%, here is the gdb result :
OK I just talked to Paolo about this, and it's fairly serious.
Can you get a core dump from this?
You will need to set up the ulimit etc as outlined in the previous
then run the conversion until it hangs, then 'killall -BUS qemu-img'
which should cause qemu-img to drop a core dump file.
You can send me (privately) the core dump and I will open a BZ about this and ensure that the necessary people see this.
> (gdb) t a a bt
> Thread 2 (Thread 0x7f0f3cea9700 (LWP 9583)):
> #0 sem_timedwait () at
> #1 0x00007f0f45b765e7 in qemu_sem_timedwait ()
> #2 0x00007f0f45b0750c in worker_thread ()
> #3 0x00007f0f4203bdf3 in start_thread (arg=0x7f0f3cea9700) at
> #4 0x00007f0f41d6901d in clone () at
> Thread 1 (Thread 0x7f0f45aa88c0 (LWP 9582)):
> #0 0x00007f0f41d5eb0f in __GI_ppoll (fds=0x7f0f470d7a00, nfds=1,
> timeout=<optimized out>, sigmask=0x0) at
> #1 0x00007f0f45b146db in qemu_poll_ns ()
> #2 0x00007f0f45b15430 in aio_poll ()
> #3 0x00007f0f45b0eedd in bdrv_prwv_co ()
> #4 0x00007f0f45b0efd3 in bdrv_rw_co ()
> #5 0x00007f0f45b05b35 in img_convert ()
> #6 0x00007f0f41c94af5 in __libc_start_main (main=0x7f0f45b01e80 <main>, argc=10, ubp_av=0x7fff19cb3ab8, init=<optimized out>, fini=<optimized out>,
> rtld_fini=<optimized out>, stack_end=0x7fff19cb3aa8) at
> #7 0x00007f0f45b022ed in _start ()
> -----Message d'origine-----
> De : Richard W.M. Jones [mailto:rjones at redhat.com] Envoyé : mardi 14
> octobre 2014 22:52 À : VONDRA Alain Cc : libguestfs at redhat.com Objet :
> Re: [Libguestfs] Virt-v2v conversion issue
> On Tue, Oct 14, 2014 at 03:40:22PM +0000, VONDRA Alain wrote:
> > Rich,
> > I've followed your instructions to trace, but I am not very skilful with gdb, maybe I made a mistake :
> > (1) As root do:
> > echo core.%p > /proc/sys/kernel/core_pattern -> OK
> > (2) Before running virt-v2v, do:
> > ulimited -c unlimited -> I think it's ulimit -c unlimited -> -> OK
> > and you should get a core.* file in the current directory when qemu-img segfaults. Attach that file to gdb to get a stack trace:
> > gdb /usr/bin/qemu-img core.XYZ -> Do I need to wait the crash becase I don't have any core ???
> Yes, you have to wait for qemu-img to crash before there will be a core dump. If it's not crashing, then connect to qemu-img directly, something like this:
> gdb /usr/bin/qemu-img `pidof qemu-img`
> and run this command:
> > (gdb) t a a bt
> to show the stack trace in all threads.
> If qemu-img is consuming CPU then it's probably not hung.
> I'm still interested to find out why fstrim didn't work. Can you run:
> guestfish --ro -d unc-srv-qual03
> ><fs> run
> ><fs> part-list /dev/sda
> ><fs> part-list /dev/sdb
> ><fs> part-list /dev/sdc
> ><fs> part-list /dev/sdd
> I'd be interested to see if the partitions are unaligned, which is the only reason why fstrim should fail on NTFS.
> Richard Jones, Virtualization Group, Red Hat
> http://people.redhat.com/~rjones Read my programming and
> virtualization blog: http://rwmj.wordpress.com virt-builder quickly
> builds VMs from scratch http://libguestfs.org/virt-builder.1.html
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org
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