Overview

By default, Avance provides protection against disk faults.   In version R3.1 and greater you can also gain protection against catastrophic storage controller failures by enabling the Enhanced Storage Protection feature. Enabling this feature allows VMs to migrate gracefully to the other PM in the event of a storage controller fault.

Enabling/Disabling

Currently this feature is only available on Dell systems with at least 32 GB of memory on each PM,  and at least 12GB of memory free that is not assigned to running VMS.   Enabling this feature will result in the additional allocation of 12GB of memory for the Avance/Xen management stack.  There are two ways in which the feature can be enabled.

• During Installation
  If your machine meets the minimum requirements mentioned above, you will be able to enable the Enhanced Storage Protection feature at the Configuration screen.
• Post Installation
  In the Avance Management Console, go to the Preferences > System Resources page and click Enable or Disable under Enhanced Storage Protection.   Regardless of whether the feature is enabled or disabled each PM requires a reboot in order for the new settings to take affect.    This is referred to as a “Rolling Reboot”.    In R3.1 there is a new Rolling Reboot button at the Top-Level Unit page.   This will cycle through each PM to do a reboot by placing each in maintenance mode.   Note that the VMs will continue to run through a rolling reboot since one PM is always up and running.

Recovery

Avance is capable of recovering from any single physical or logical disk failure gracefully.   However, in the event of the loss of your system disks or a catastrophic controller failure the system will need to be placed in maintenance, repaired, and the “Recovered” via the Avance Management Console.