Is there any side affect of cancelling (Ctrl + c or killing k.exe) for "arc

No. You can safely kill the process. Remember that unarchiving is resource intensive and can take a considerable amount of time depending on the number of archived processes.

What you may want to do is run a search for that process ID under the archive-processes folder to find the corresponding file and to do a faster procedure simply run:

archiveprocess unarchive -pid 1076070500 -file XXXXXXXXXXX.l

where XXXXXXXXXXX.l is the name of the file you found when searching for the process id on disk.

No. You can safely kill the process. Remember that unarchiving is resource intensive and can take a considerable amount of time depending on the number of archived processes.

What you may want to do is run a search for that process ID under the archive-processes folder to find the corresponding file and to do a faster procedure simply run:

archiveprocess unarchive -pid 1076070500 -file XXXXXXXXXXX.l

where XXXXXXXXXXX.l is the name of the file you found when searching for the process id on disk.