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

[Dongli Zhang]

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.

So far I am reproducing the issue with NFS (by shutdown the link to NFS where
the image is placed on purpose) but it did not work well.

> 
>>
>> For instance, I would like to observe/study/debug the I/O timeout handling of
>> nvme, scsi, virtio-blk (not supported) of VM kernel.
>>
>> Is there a way to trigger this on purpose on qemu side?
>>
>> Thank you very much!
>>
>> Dongli Zhang
>>
>>
> 

Dongli Zhang