When using SSH to access one of your servers, you may be greeted with the following message:
Your Hardware Enablement Stack (HWE) is supported until April 2017
The HWE is an Ubuntu feature providing LTS releases (Precise Pagolin in Acquia Cloud) with hardware support introduced in newer Ubuntu releases. You can find more information regarding the exact nature of HWE, if you are interested, at http://askubuntu.com/questions/248914/what-is-hardware-enablement-hwe and https://wiki.ubuntu.com/1204_HWE_EOL.
Once your server OS is upgraded to Xenial, you will not see the message any longer.
For more information about this upgrade, see our article, "Ubuntu 12.04 LTS (Precise) to Ubuntu 16.04 LTS (Xenial) Upgrade FAQ".