> I would argue that a rack-mounted chassis with lots of disks is also ephemeral, just less so: most failures in a server can be fixed by swapping some parts, a

> I would argue that a rack-mounted chassis with lots of disks is also ephemeral, just less so: most failures in a server can be fixed by swapping some parts, and your data is still there. True but this also depends on design decisions AWS made with regards to those volumes. Indeed it could be that the volume is internally (at the hypervisor level) redundant (maybe with something like ZFS or other proprietary RAID), but there's no way to know. Furthermore, AWS doesn't allow you to really keep a tab or reservation on the physical machine your VM is on - every time a VM is powered up, it gets assigned a random host machine. If there is a hardware failure they advise you to reboot the instance so it gets rescheduled on another machine, so even though technically your data may still be on that physical host machine, you have no way to get it back. AWS' intent with these seems to be to act as transient cache/scratchpad so they don't seem to offer much durability or recovery strategies for those volumes. Their hypervisor seems to treat them as disposable which is a fair design decision considering the planned use-case, but it means you can't/shouldn't use it for any persistent data. Being in control of your own hardware (or at the very least, renting physical hardware from a provider as opposed to a VM like in AWS) will indeed allow you to get reliable direct-attach storage.