This gaiterjones Blog article recommends:
Redis can be configured to automatically save (or persist) cached data to disk, this is really useful for volatile cache data, i.e. data you do not want to lose. Essentially redis saves a dump of the cache data regularly to disk (in /var/lib/redis) so that if the redis instance crashes or the server is restarted the cached data is not lost. This is great for cached Magento session data, we want this data in fast cache storage but we do not want to lose the data unlike system and full page cache data where we don’t really care if the data is lost – it will just be cached again.
I've looked everywhere I can think of, but no-one else seems to be recommending this approach, and Colin Mollenhour ( ColinM ) makes no mention or recommendation... yet I can see the logic of what the approach suggests as RAM accesss should be quicker and it avoids i.o. of periodic writes. Are there any disadvantages to following this approach?
Secondly, in a cloud environment if I were to later down the line, decide to have a cluster and spin up new instances would they require access to a snapshot on launch?