[tasaro]

I haven't seen anyone mention the cost of IO requests associated with EBS. Quoted from http://aws.amazon.com/ebs/ :

As an example, a medium sized website database might be 100 GB in size and expect to average 100 I/Os per second over the course of a month. This would translate to $10 per month in storage costs (100 GB x $0.10/month), and approximately $26 per month in request costs (~2.6 million seconds/month x 100 I/O per second $0.10 per million I/O).

[jread]

I'm running 4 m1.small EBS-backed LAMP servers in all 4 regions. I pay about $1/mo for EBS IO (8-11 million IO requests per instance per month). The servers get a few thousand hits per day. The cost of EBS IO should be minimal in most cases. The benefit of EBS versus the local storage you'll get with Rackspace or Linode is greater durability because it is off instance and AWS automatically duplicates the data. If the VM host system fails (i.e. power supply goes bad), you can bring your instance back online within a very short period of time on another host at the exact state it was at the time of failure.

[shykes]

One word of caution: sometimes when an instance becomes unavailable (think network partitioning), all its EBS volumes will become unavailable as well. You can't snapshot, you can't detach. My most frustrating experience on EC2 yet.

[JeffJenkins]

You can force detach using the console tools. I had this problem too

[shykes]

I can remember at least one case where force-detach didn't work either. In that case there is absolutely nothing you can do to access your data.