I was moving emails from old Zimbra installation on new Carbonio and was getting this error when trying to import user from tgz archive:
root@mail:/opt/backup# /opt/zextras/bin/zmmailbox -z -m mymail@mydomain.com postRestURL '//?fmt=tgz&resolve=skip' /opt/backup/mymail@mydomain.com.tgz
ERROR: zclient.IO_ERROR (Read timed out) (cause: java.net.SocketTimeoutException Read timed out)
There was a timeout causing this. So after quick googling around I found this solution that works:
root@mail:/opt/backup# su - zextras
zextras@mail:~$ zmlocalconfig -e socket_so_timeout=3000000
Then your restore command should work without timeout. At the end, you can reset socket_so_timeout value:
root@mail:/opt/backup# su - zextras
zmlocalconfig -u socket_so_timeout