[SteveNuts]

> Jails haven't been used to protect as many high-value targets as Linux containers have

This is not true in my experience at all. It may be true that it hasn't been in use at startups until Docker came out, but a few large, established companies I've worked at absolutely used Jails or Zones to protect their most valuable IP. And have been for a long time.

[geofft]

What was the attack surface of the jails/zones? I don't think the distinction here is startup vs. large company but internal vs. external. We used jails at my last company as a last line of defense (and, full disclosure, I wrote about 100 lines of code to use unshare(1) etc. when that machine was our last FreeBSD box remaining in our Linux conversion), but it was on a non-internet-accessible server where the jailed network connection was routed only to a single other (much larger) business that we had an established relationship with. If attacker code were executing inside the jail, there was already a serious breach.

The distinction here is that people are running containers in the cloud and also often running untrusted code (e.g. vendor software, random exciting open-source things) inside containers, and collocating those with high-value targets in other containers. And large, established companies are doing that now just as much as startups are.