[CRIU] Difference between two snapshots generated by CRIU

[Pavel Emelyanov]

On 02/10/2015 02:30 PM, Thouraya TH wrote:
> Hello all,  i have done two times the dumping process of this process http://criu.org/Simple_loop
> 
> root at g-52:/home# *cd LoopProcess*
> root at g-52:/home/LoopProcess# ls
> cgroup.img      dump.log       fdinfo-2.img   fs-9162.img   inotify.img    ns-files.img      pages-2.img     remap-fpath.img   stats-dump    unixsk.img
> core-9162.img   eventfd.img    fdinfo-3.img   fs-9773.img   inventory.img  packetsk.img      pipes-data.img  sigacts-9162.img  timerfd.img
> core-9773.img   eventpoll.img  fifo-data.img  ids-9162.img  mm-9162.img    pagemap-9162.img  pipes.img       sigacts-9773.img  tty.img
> creds-9162.img  ext-files.img  fifo.img       ids-9773.img  mm-9773.img    pagemap-9773.img  pstree.img      signalfd.img      tty-info.img
> creds-9773.img  fanotify.img   filelocks.img  inetsk.img    netlinksk.img  pages-1.img       reg-files.img   sk-queues.img     tunfile.img
> 
> root at g-52:/home/LoopProcess# cd ..
> root at g-52:/home# *cd LoopProcess1/*
> root at g-52:/home/LoopProcess1# ls
> cgroup.img       dump.log       fdinfo-2.img   fs-10821.img   inotify.img    ns-files.img       pages-2.img     remap-fpath.img    stats-dump    unixsk.img
> core-10821.img   eventfd.img    fdinfo-3.img   fs-9162.img    inventory.img  packetsk.img       pipes-data.img  sigacts-10821.img  timerfd.img
> core-9162.img    eventpoll.img  fifo-data.img  ids-10821.img  mm-10821.img   pagemap-10821.img  pipes.img       sigacts-9162.img   tty.img
> creds-10821.img  ext-files.img  fifo.img       ids-9162.img   mm-9162.img    pagemap-9162.img   pstree.img      signalfd.img       tty-info.img
> creds-9162.img   fanotify.img   filelocks.img  inetsk.img     netlinksk.img  pages-1.img        reg-files.img   sk-queues.img      tunfile.img
> 
> Then:
> 
> criu show -D LoopProcess 
> i see many lines.. i'd like to redirect the result of this command to a file like that:
> 
> criu show -D LoopProcess > first.txt
> 
> but i have these error :
> Error (image.c:231): Unable to open netdev-2.img: No such file or directory
> Error (image.c:231): Unable to open ifaddr-2.img: No such file or directory
> Error (image.c:231): Unable to open route-2.img: No such file or directory
> Error (image.c:231): Unable to open iptables-2.img: No such file or directory
> Error (image.c:231): Unable to open ipcns-var-3.img: No such file or directory
> Error (image.c:231): Unable to open ipcns-shm-3.img: No such file or directory
> Error (image.c:231): Unable to open ipcns-msg-3.img: No such file or directory
> Error (image.c:231): Unable to open ipcns-sem-3.img: No such file or directory
> Error (image.c:231): Unable to open utsns-4.img: No such file or directory
> Error (image.c:231): Unable to open mountpoints-5.img: No such file or directory

The criu show -D doesn't work reliably. We used to have one in the ealy stages of development
and then forgot to drop :) The only way that is guaranteed to work is per-file one, i.e. the
"criu show -f $image-file" one.

We plan to drop the "show" functionality eventually and replace it with the crit tool
(http://criu.org/CRIT). CRIT will generate the JSON output.

Thanks,
Pavel