Posted June 03, 2021
nightcraw1er.488: No, a backup is a copy of something. Raid is a method of combining disks, which can include various levels of failsafe if one or more of the drives fail. Whilst you can of course use raid drives as backups, and I have five different raid boxes now, it is the number of backups which is vital, not the methodology. 3 external drives is just as good as 3 raid setups when discussing backups and is far cheaper. In terms of bitrot, and general practice, I recommend time point backups in addition to regular backups. So you could have two or 3 drives which you regularly update on a cycle, and then 1 or 2 drives which you only update every other year or so, and are used very minimal. I have this also, I have backups way back to 2005 which have only been written to once. I can always go back then. Also, different locations is key, don’t stick all your eggs in one house, offsite ones (maybe one or the other timepoint?) cover serious issues like house fire.
kohlrak: While the average gog user is more likely to experience bitrot than a fire (and if you deal with a fire you also are mot likely to have more important concerns than your gog library), your points are valid, except the point against methodology. The important part with methodology is that you have to have a reliable recovery method in the event that "something goes wrong," because not only can you end up with corruption or a sector or two, but the same files can each end up corrupted. Thus you want to be able to more or less democratize the data, since the likelihood of the same bytes being corrupted is near zero. Ideally, not just a different house, but several miles/kilometers away, due to natural disasters that can affect multiple houses at once (floods, surges[if in use], explosions [more likely than you would expect, these days, but less likely than a fire, obviously], EMPs [not likely at all], tornados [very likely for some people], etc). At the same time, to be practical, one has to be able to bring them together again to actaully do the comparisons.
Another alternative is 2 separate drives with triple redundancy (3 copies of the same folder) within the drives themselves if you don't need that much space.If someone nukes your house, you still have the triple redundancy hiding out in Dyatlov Pass.