[Libguestfs] [Qemu-devel] How to emulate block I/O timeout on qemu side?

Richard W.M. Jones rjones at redhat.com
Tue Nov 6 09:14:57 UTC 2018

On Tue, Nov 06, 2018 at 02:17:46PM +0800, Dongli Zhang wrote:
> On 11/06/2018 01:49 AM, Eric Blake wrote:
> > On 11/2/18 3:11 AM, Dongli Zhang wrote:
> >> Hi,
> >>
> >> Is there any way to emulate I/O timeout on qemu side (not fault
> >> injection in VM kernel) without modifying qemu source code?
> >
> > You may be interested in Rich's work on nbdkit.  If you don't mind
> > the overhead of the host connecting through NBD, then you can use
> > nbdkit's delay and fault-injection filters for inserting delays or
> > even run-time-controllable failures to investigate how the guest
> > reacts to those situations
> >
> Thank you all very much for the suggestions. I will take a look on nbdkit.

These links should help:


This link shows how to combine delay and error filters together:



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