<div dir="ltr"><div>On Tue, Jul 15, 2014 at 8:08 AM, Pavel Emelyanov <span dir="ltr"><<a href="mailto:xemul@parallels.com" target="_blank">xemul@parallels.com</a>></span> wrote:<br></div><div class="gmail_extra"><div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div class="">On 07/15/2014 06:49 PM, Pavel Emelyanov wrote:<br>
> On 07/15/2014 06:34 PM, Saied Kazemi wrote:<br>
>> Thanks for the quick feedback. I am using CRIU 1.3-rc2 (at commit e1b56c8fa) with Docker version<br>
>> 1.1.0 on Ubuntu 14.04 which does not provide mnt_id in /proc/pid/fdinfo/fd files.<br>
><br>
> That can be a problem.<br>
><br>
>> I will look into Docker source today. Assuming that it does open /dev/null before moving into the<br>
>> namespaces, can CRIU handle it?<br>
><br>
> It should, but without this field this would fail just the<br>
> way you observe with Docker :)<br>
<br>
</div>After refreshing my memory and talking to Andrey (who wrote this code) the<br>
answer is -- no. When we have multiple mount namespaces files opened from<br>
outside are not dumped.<br></blockquote><div><br></div><div>Is this because this case cannot be technically supported, or is it because it has been a marginal case so far?</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
For /dev/null you could consider using the --evasive-devices option. It will<br>
ask criu to dump the device's path in whichever location it's found. Not<br>
sure how would this affect Docker though.<br></blockquote><div><br></div><div>The good news is that using --evasive-devices, it's possible to dump and restore the process. But, as you said, I am not sure yet how this would affect Docker. Will look into it.</div>
<div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div class=""><div class="h5">> If you could confirm that on<br>
> the kernel with mnt_id in fdinfo it works, that would be<br>
> great. Meanwhile, I will try to make a test for this.<br></div></div></blockquote><div><br></div><div>Will have to find a kernel with mnt_id support and repeat the tests. This may take a while.</div><div><br></div>
<div>Thanks,</div><div><br></div><div>--Saied</div><div> </div></div></div></div>