[CRIU] Criu Restore Error

[Christopher Covington]

Hi Priyanka,

On 03/25/2015 11:49 AM, Priyanka Naik wrote:
> On 25 Mar 2015 21:09, "Priyanka Naik" <prnk.nk1 at gmail.com
> <mailto:prnk.nk1 at gmail.com>> wrote:
> 
>     That is fine that I should provide u with log files but my guest does not
>     scroll bcoz of which I m nt able to see the errors and not even able to
>     take that file out of guest.

Try adding these QEMU arguments:

  -nographic -monitor none -serial stdio

>     So he suggested me the way of mounting my vdisk.img but the steps as I
>     told you gave me errors. So I m unable to proceed.

If you use the 9P passthrough filesystem I mentioned, there's no extra work to
get files out of the guest--they're always available to the host.

Chris

>     On 25 Mar 2015 21:01, "Christopher Covington" <cov at codeaurora.org
>     <mailto:cov at codeaurora.org>> wrote:
> 
>         Hi Priyanka,
> 
>         On 03/24/2015 01:31 AM, Priyanka Naik wrote:
>         > I m running a sample process on my host machine and dumping it on
>         the host. If
>         > i try to restore the process on the host OS, the process gets
>         restored back
>         > successfully. But now I m tarring my dumped files directory into a
>         .tgz file
>         > and sending it to guest using virtIO serial as the medium of
>         transfer. The
>         > transfer of dumped files take place successfully as I m checking the
>         hash
>         > values of both the files using md5sum. I m untarring it on guest and
>         trying to
>         > restore it back on the guest system but due to some reasons we are
>         unable to
>         > restore it back on the guest system.
> 
>         Perhaps file transfer over serial is more useful to you, but in my
>         environment
>         I've found the 9P passthrough filesystem to be the easiest way to
>         transfer files.
> 
>         http://www.linux-kvm.org/page/9p_virtio
>         http://wiki.qemu.org/Documentation/9psetup
> 
>         (If you want a 9P *rootfs*, which is what I use, you'll need the
>         following in
>         your kernel command line:
> 
>         rootfstype=9p rootflags=trans=virtio,version=9p2000.L
> 
>         You'll also need to use the mount tag "/dev/root" and/or add
>         "root=<mount_tag>" to the kernel command line.)
> 
>         > Firstly to start the guest we are using following command :
>         >
>         > qemu-system-x86_64 -m 1024 -s -hda vdisk.img -kernel
>         > /usr/src/linux-3.17.6/arch/x86_64/boot/bzImage -initrd
>         > /home/priyanka/tmp2/newinitrd.img -append "root=/dev/sda10" -name
>         myguest
>         > -device virtio-serial -chardev socket,path=/tmp/foo,server,nowait,id=foo
>         > -device virtserialport,chardev=foo,name=org.fedoraproject.port.0
>         >
>         > Now once we boot the system and type the tty command on the guest we get
>         > /dev/console and if we type tty on host it gives output as
>         /dev/pts/no i.e.
>         > some number associated with that terminal. We checked with the code
>         of tty.c
>         > which has facilities for both PTS and CONSOLE. But we are not
>         getting the
>         > exact reason for criu not working on guest, since we are creating
>         exact copy
>         > of the kernel on host system, the guest should have all the facilities
>         > required for criu since criu is working on host.
>         >
>         > And as Cyrill said that we need /dev/ptmx on guest, so it is
>         present. Even
>         > /dev/pts/ptmx is present.
>         >
>         > What can be the problems on guest side which will make our project
>         work? What
>         > is exactly going wrong?
> 
>         You may be able to work around the issue by redirecting STDIN, STDOUT, and
>         STDERR from and to files. That's what I've been doing on ARM where
>         ttyAMA (ARM
>         PL011 serial) hasn't historically been supported (although maybe
>         that's been
>         fixed now). Example:
> 
>         app /share/suite/app/input < /dev/null &> app.log &
> 
>         The full log that Pavel was talking about (contents of logfile from
>         `criu -v4
>         > logfile` or criu -v4 -o logfile`) would have details about what
>         exactly is
>         going wrong.
> 
>         Hope that helps,
>         Chris
> 
>         --
>         Qualcomm Innovation Center, Inc.
>         The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>         a Linux Foundation Collaborative Project
> 


-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project