X forwarding in ssh

To enable X forwarding, try the following command
ssh -X xxx.xxx.xxx.xxx

than we can launch a program with GUI through ssh.

Sometimes it does not work as expected, check the DISPLAY environment variable.

export DISPLAY=:10.0

duplicate a new table in Oracle

create table [new table name] as select * from [table name]

Remove VirtualBox lock

The lock file of VirtualBox is placed in
/tmp/.vbox-[user name]-ipc