Re: [Qemu-block] [Qemu-devel] I/O errors reported to guest for raw-image-file backed /dev/vda - but host sees no I/O errors
On 04/22/2016 03:16 AM, Fam Zheng wrote: On Thu, 04/21 17:54, Lutz Vieweg wrote: Nevertheless, I think qemu could be somewhat more verbose, reporting when and why it stops emulation. Something like a message to the monitor or to standard out would be helpful to start with... QEMU does report an error message to connected monitor if configured to. See the werror= and rerror= options. I looked up these options, but both the man-page and the source code did not reveal any option to emit error messages to the qemu monitor - the "report" option value just causes the guest to see the error code, but that doesn't mean a message to the qemu monitor. Regards, Lutz Vieweg
Re: [Qemu-block] [Qemu-devel] I/O errors reported to guest for raw-image-file backed /dev/vda - but host sees no I/O errors
On Thu, 04/21 17:54, Lutz Vieweg wrote: > Nevertheless, I think qemu could be somewhat more verbose, reporting > when and why it stops emulation. Something like a message to the monitor > or to standard out would be helpful to start with... QEMU does report an error message to connected monitor if configured to. See the werror= and rerror= options. Fam
Re: [Qemu-block] [Qemu-devel] I/O errors reported to guest for raw-image-file backed /dev/vda - but host sees no I/O errors
On 04/20/2016 01:50 PM, Kevin Wolf wrote: To catch all possible write failures, I think pwrite, pwritev and possibly fdatasync need to be considered. I've now a strace -f -p 10727 -e trace=pwrite,pwritev,fdatasync,file -t 2>&1 | gzip -1 -c >trace.gz attached to the qemu-process. If the incident rate stays the same, by tomorrow I should be able to correlate newly emitted I/O-errors in the guest with that log. Regards, Lutz Vieweg
