Re: Long ago.
We have 5 nominally identical machines used for "industrial control" use, all around 6 years old now. But one of them turned out to crash at roughly 2-6 month intervals. Memory tests, etc, revealed nothing. Second time it happened it was at 9.30pm on a Friday night while I was out for a beer or three and I had to persuade the security guy to let me in and up to the top floor to push the reset button.
After that we put watchdog daemons on all of them (and quite a few other machines as well) and in practically every case it has saved physical intervention to restore operations.
Top tip - edit your settings so the machine just fixes any file system anomalies and continues, and is not sitting there prompting you to decide on the action. For example:
In general most modern file systems will be OK for any automatic repair, if not then you were going to have to reformat and restore your backup anyway...