The only reasonable assumption is circumstances that do not involve hardware failure, the binary being compiled incorrectly, the source code being modified or replaced by someone downstream, the libraries it is using being corrupt or having been replaced by ABI-incompatible variants... none of these are reasonable circumstances; one would then further assume that the person posting has run into reasonable circumstances where MongoDB often crashes, which is not a stretch given the number of bugs that are filed against it that talk about this kind of issue.
Exactly; well said. It's been about a year but basically I had a replica set where sometimes one replica or the other would segfault and I'd have to manually delete its data files and re-replicate, after which it was fine. Happened about every few months. It was clearly based on application behavior and not an inherent system problem such as those you listed.
https://www.google.com/search?q=site:jira.mongodb.org+mongod...