AWS Questions: EBS

So, more questions about AWS from students (and my own research/curiosity):

• What happens when general purpose ebs volumes run out of credit because you’ve used too many IOPS?
  • Your disk performance reverts to the baseline performance: “If your gp2 volume uses all of its I/O credit balance, the maximum IOPS performance of the volume will remain at the baseline IOPS performance level (the rate at which your volume earns credits) and the volume’s maximum throughput is reduced to the baseline IOPS multiplied by the maximum I/O size.”
• Before you take a snapshot you should quiesce the disk.  Can you do that via an AWS command?
  • You need to use whatever operating system or application command is recommended.  You can use EC2Run to execute that command, but you must determine what that command is.  From the backup and recovery whitepaper: “For this reason, you must quiesce the file system or database in order to make a clean backup. The way in which you do this depends on your database or file system. ”  Note also that the quiescing of the disk can be for only a few seconds, as the EBS snapshot process can be started quickly, though it may take a while to complete.
• Can you be notified of snapshot completion via an event or do you have to poll?
  • You can use cloudwatch events to be notified.
• Can you automate your EBS snapshots?
  • Yes
• Does EBS encryption cost extra?
  • Nope: “This frequently requested feature provides you with seamless support for data encryption on block-level storage, at no additional cost.”