[Libguestfs] question about backing file path of a qcow2 image

[Richard W.M. Jones]

On Thu, Sep 12, 2013 at 10:46:12AM +0800, bigclouds wrote:
> thanks . now i know qcow2 only store relative path.
> look at my error message,  6a3256bb-b247-4fb5-9f75-8ffa7151eeda  i a symlink to a LV. it is the backing_file of several images(LV)..
> i have no idea of  the reason of the error.
> 
> # virt-win-reg 6a3256bb-b247-4fb5-9f75-8ffa7151eeda 'HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion' 'Productname'
> hivex: /tmp/libguestfsIdLWuF/0-software: trailing garbage at end of file (at 0x86e000, after 2088 pages)
> hivex_open: Operation not supported at /usr/bin/virt-win-reg line 259.

This error indicates that hivex cannot parse the SOFTWARE hive in this
guest.  If you truly think this hive is not corrupt but that it's a
parsing bug in hivex, then you can download the hive from this 'guest'
and attach it to a bug against hivex.

You can set HIVEX_DEBUG=1 to get more debugging information from
hivex, which will tell you the actual problem that hivex is
encountering.

You mention that '6a3256bb-b247-4fb5-9f75-8ffa7151eeda' is a backing
file for other guests.  It's not always valid to directly open backing
files (it depends on how it was created and updated).  If the backing
file isn't a full guest image, then it is expected that the operation
above would not work.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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