[Libguestfs] Plans for changing libguestfs appliance building

[Jin Xin Zheng]

On 08/16/2010 06:40 PM, Richard W.M. Jones wrote:
> On Mon, Aug 16, 2010 at 10:17:30AM +0800, Jin Xin Zheng wrote:
>    
>> The virtual cdrom device in qemu will be readonly (is that right?).
>>
>> Then how are you going to tune the boot process as I know it would
>> require writing to the filesystem.
>>      
> I'm not aware of us needing to write to the root filesystem during
> boot (well, there is one place where we do 'mkdir -p /sysroot' but
> that can be fixed).
>
> However there is an issue that we modify configuration files in the
> daemon, in particular /etc/lvm/lvm.conf, which would require either
> making this directory a tmpfs or using some other method to make root
> writable.
>
> Rich.
>
>    
Are you sure all the binary utils inside the appliance will not write
logging files when running?

In fact when I saw this the first thing came up to my head was that our
modified source for doing gcov -- we could collect the .gcda files in
the build directory after libguestfs was invoked. But the guestfsd which
runs inside the appliance produces the .gcda files in the temp ramfs.
We have made a pretty lot of effort in order to tar-out these files
before the subprocess was killed.

If the filesystem is readonly then I'll have to do more to allow guestfsd
to write debugging coverage info into a writable place. However this is
not a problem for libguestfs, it's just a problem for me...


-- 
Regards.
Jinxin