At 20:58 PST our engineers have been notified about an outage on node v426. The cause of the outage was quickly established (kernel panic).
At 21:16 PST we have applied a fix to the node and it will be restarted shortly.
At 21:18 PST node was restarted and all VMs should start automatically in the next 15 minutes. We will be keeping an eye on this node to make sure there are no other issues.