Amongst the many interesting discussions I had at Build Stuff last week was about how it’s desirable to switch off disk caching for the disks used for Event Store databases to help ensure that data is durable in the face of power failures.
This is actually true of many databases, indeed, postgres gives you a warning about the possible dire consequences of having write caching switched on when you may experience power failure.
Obviously here you should replace /dev/sda with whichever device your database is on!
Note that simply disabling drive caching is actually not enough to ensure that writes are durable – many drives still misbehave (especially the Intel 520 series SSDs)!