Yeah that does sound like the symptoms of the problem I discovered. If you ever witness it again, the trick is watching /proc/meminfo for the Dirty and Writebac

Yeah that does sound like the symptoms of the problem I discovered. If you ever witness it again, the trick is watching /proc/meminfo for the Dirty and Writeback numbers. And it's the vm.dirty* settings to change to fix it as described here: https://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/ https://lonesysadmin.net/2013/12/22/better-linux-disk-cachin...