While I've experienced some of the same issues as the author, and came to the same conclusion (that we couldn't use Redis in VM mode in production), the subject line is unfairly alarmist.

We are using Redis in production (we had to adapt our usage patterns to the demands of an in-memory database, rather than relying on VM to give us unlimited storage) and I would recommend it.

"Considered harmful" is not warranted here: see http://meyerweb.com/eric/comment/chech.html

this is exactly the reason why salvatore has been working on diskstore for the 2.4 release. redis + VM in production is indeed a bad idea.

The thread this post links to is actually quite interesting as you can pretty much read the design changes that led from VM to the new diskstore implementation. The sensationalist title here doesn't help at all - I don't think people who are making heavy use of Redis in production are 1) using VM and 2) unaware of VMs problems if using it.