Migration from oneffs -> oneffs-fail-safe

[reynir]

No description provided.

[hannesm]

I thought about this, and I think a library function would be great. Since if we're in a albatross-hosted environment we don't really want to have OCaml tools installed on the host system and a unikernel operator doesn't have shell access.

So, a unikernel - such as mollymawk - that uses at the moment oneffs should be able in its startup:

• read block device as oneffs
• if successful, convert to fail-safe (if the block device is big enough, this should succeed. otherwise not)
• if not successful, read as fail-safe
• if that second reading does not succeed, format as fail-safe.