Re: KVM Block Device Driver

["Spensky, Chad - 0559 - MITLL" <chad.spensky@ll.mit.edu>]

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Wolf,

  We're able to get all of the meta data just fine.  However it seems that
the actual content of the read/write seems to be wrong some of the time.
The first 2 sectors seem to always be correct, however on some writes, the
data that we traced does not match up with the data we are actually seeing
in the .img file for the guest on disk.

 - Chad

-- 
Chad S. Spensky

MIT Lincoln Laboratory
Group 59 (Cyber Systems Assessment)
Ph: (781) 981-4173





On 8/14/13 10:40 AM, "Wolfgang Richter" <wolf@cs.cmu.edu> wrote:

>Still interested and back to working on this.  I taught a couple
>classes this summer which killed my time in June - July.
>
>So Chad, are you already logging all accesses? Or do you need
>something quick to log them?
>
>I have a patch to QEMU mainline (very small) to add block I/O tracing,
>but it works via the log subsystem and might not fit your environment
>if you wanted a production solution.
>
>--
>Wolf
>
>On Wed, Aug 14, 2013 at 10:07 AM, Stefan Hajnoczi <stefanha@gmail.com>
>wrote:
>> On Wed, Aug 14, 2013 at 07:29:53AM -0400, Spensky, Chad - 0559 - MITLL
>>wrote:
>>>   We are trying to keep an active shadow copy while the system is
>>>running
>>> without any need for pausing.  More precisely we want to log every
>>> individual access to the drive into a database so that the entire
>>>stream
>>> of accesses could be replayed at a later time.
>>
>> CCing Wolfgang Richter who was previously interested in block I/O
>> tracing:
>> https://lists.nongnu.org/archive/html/qemu-devel/2013-05/msg01725.html
>>
>> Stefan
>
>
>
>-- 
>Wolf

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