Received an email from Linode about the security updates. It happened on yesterday.
The Email said:
Linode recently received several Xen Security Advisories (XSAs) that require us to perform updates to our host servers. In order to apply the updates, hosts and the Linodes running on them must be rebooted. The XSAs will be publicly released by the Xen project team on March 10th, therefore we must complete the updates before that date.
These updates are required to protect the security and safe operations of not only our infrastructure, but yours as well. We understand that a disruption with such limited notice is inconvenient, and we hope you understand that these measures are warranted due to the severity of the XSAs.
Your Linodes have been assigned a maintenance window in which a reboot will occur. These times are listed within the Linode Manager in the timezone set in your user’s My Profile. Your schedule in UTC timezone is as follows:
* 2015-03-08 3:00:00 PM UTC – linodexxxxxx
During the maintenance window Linode instances will be cleanly shut down while we perform the updates. Your Linode will be inaccessible during this time. A two-hour window is allocated, however the actual downtime can be much less. After the maintenance, each Linode will then be booted. See our Reboot Survival Guide for tips and hints on configuring and testing that your Linode services boot properly after the maintenance.
Unfortunately, due the logistical demands of this effort, your assigned windows are not changeable and the host reboots are mandatory.
It is about one hour sever down time on my VPS.