There are automated solutions to this. Windows has had similar tricks built in (at various levels of cleverness, depending on the Windows variant you run) for

There are automated solutions to this. Windows has had similar tricks built in (at various levels of cleverness, depending on the Windows variant you run) for a while now: https://en.wikipedia.org/wiki/Prefetcher https://en.wikipedia.org/wiki/Prefetcher No doubt there are similar options for Linux and other OSs. A similar trick I've seen is using a small SSD as a manual cache: copy in the files that need to be fast and mount it with the larger filesystem (on slower drives) as a unioned filesystem. Though just using block device based automatic cacheing may be easier and safer than rolling your own mess. There are a few options for Linux though some are not currently maintained (see https://serverfault.com/questions/969302/linux-ssd-as-hdd-cache https://serverfault.com/questions/969302/linux-ssd-as-hdd-ca... amongst other places), and some IO controllers support it directly (even some motherboards have this built in) without needing to bother your OS with the details at all.