Re: [Qemu-block] [Qemu-devel] [BUG] qed_aio_write_alloc: Assertion `s->allocating_acb == NULL' failed.

[John Snow]

CC Qemu Block; looks like QED is a bit busted.

On 06/27/2018 10:25 AM, Quytelda Kahja wrote:
> Hello all,
> I wanted to submit a bug report in the tracker, but it seem to require
> an Ubuntu One account, which I'm having trouble with, so I'll just
> give it here and hopefully somebody can make use of it.  The issue
> seems to be in an experimental format, so it's likely not very
> consequential anyway.
> 
> For the sake of anyone else simply googling for a workaround, I'll
> just paste in the (cleaned up) brief IRC conversation about my issue
> from the official channel:
> <quy> I'm using QEMU version 2.12.0 on an x86_64 host (Arch Linux,
> Kernel v4.17.2), and I'm trying to create an x86_64 virtual machine
> (FreeBSD-11.1).  The VM always aborts at the same point in the
> installation (downloading 'ports.tgz') with the following error
> message:
> "qemu-system-x86_64: /build/qemu/src/qemu-2.12.0/block/qed.c:1197:
> qed_aio_write_alloc: Assertion `s->allocating_acb == NULL' failed.
> zsh: abort (core dumped)  qemu-system-x86_64 -smp 2 -m 4096
> -enable-kvm -hda freebsd/freebsd.qed -devic"
> The commands I ran to create the machine are as follows:
> "qemu-img create -f qed freebsd/freebsd.qed 16G"
> "qemu-system-x86_64 -smp 2 -m 4096 -enable-kvm -hda
> freebsd/freebsd.qed -device e1000,netdev=net0 -netdev user,id=net0
> -cdrom FreeBSD-11.1-RELEASE-amd64-bootonly.iso -boot order=d"
> I tried adding logging options with the -d flag, but I didn't get
> anything that seemed relevant, since I'm not sure what to look for.
> <stsquad> ohh what's a qed device?
> <stsquad> quy: it might be a workaround to use a qcow2 image for now
> <stsquad> ahh the wiki has a statement "It is not recommended to use
> QED for any new images. "
> <danpb> 'qed' was an experimental disk image format created by IBM
> before qcow2 v3 came along
> <danpb> honestly nothing should ever use  QED these days
> <danpb> the good ideas from QED became  qcow2v3
> <stsquad> danpb: sounds like we should put a warning on the option to
> remind users of that fact
> <danpb> quy: sounds like qed driver is simply broken - please do file
> a bug against qemu bug tracker
> <danpb> quy: but you should also really switch to qcow2
> <quy> I see; some people need to update their wikis then.  I don't
> remember where which guide I read when I first learned what little
> QEMU I know, but I remember it specifically remember it saying QED was
> the newest and most optimal format.
> <stsquad> quy: we can only be responsible for our own wiki I'm afraid...
> <danpb> if you remember where you saw that please let us know so we
> can try to get it fixed
> <quy> Thank you very much for the info; I will switch to QCOW.
> Unfortunately, I'm not sure if I will be able to file any bug reports
> in the tracker as I can't seem to log Launchpad, which it seems to
> require.
> <danpb> quy:  an email to the mailing list would suffice too if you
> can't deal with launchpad
> <danpb> kwolf: ^^^ in case you're interested in possible QED
> assertions from 2.12
> 
> If any more info is needed, feel free to email me; I'm not actually
> subscribed to this list though.
> Thank you,
> Quytelda Kahja
>