We are just migrating our cloud from Amazon Web Service to SoftLayer, and we feel really happy with performance improvement. But, somehow the new system has error like this.

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = "en_US:",
	LC_ALL = (unset),
	LC_PAPER = "id_ID.UTF-8",
	LC_ADDRESS = "id_ID.UTF-8",
	LC_NUMERIC = "id_ID.UTF-8",
	LC_CTYPE = "en_US.UTF-8",
	LC_TIME = "id_ID.UTF-8",
	LC_NAME = "id_ID.UTF-8",
	LANG = "en_US"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").

Apparently our OS doesn’t know about en_US.UTF-8, and we can easily fix this just by running this few line of commands

export LANGUAGE=en_US.UTF-8
export LC_ALL=en_US.UTF-8
sudo locale-gen
sudo dpkg-reconfigure locales