What is truly wrong with individual drives representing individual volumes with manual redundancy only on data needing it?
For instance, let’s say I have a 20TB, a 12TB, and an 8TB drive for a 4-bay NAS, then most RAID setups don’t make sense. Additionally, let’s say I really only have <8TB of data needing redundancy too… So, in this case, is there a real reason to not setup as three individual drives, with manual redundancy of necessary data; like a nightly rsync, etc.?
I get why RAID 5, say, is the most recommended, and also understand that RAID isn’t a true, completely safe backup, nor is the setup described above.
Just curious for perspectives from longer-time datahoarders. I’m a newbie to multi-drive NAS hardware.
(Also, is the scenario I described above even possible on, say, QNap or Synology; or is it only RAID or JBOD?)
Human error is the biggest factor.
You edit a file, do you directly copy it over? Probably not, so when is it time to copy over? Maybe you remember maybe you don’t.
Ohh you Deleted a File? Did you delete it on the other one aswell? No, well now we get into the rabbit hole of dependencies.
Sure you may be able to automate it via Rsync. But how often? once a day? once a month? what happens if a Drive writes faulty data and does not tell you? Well now you copied it over in the hopes it is not broken.
You want to retrive a file because you accidentially deleted it, well that file has been sitting there a long time, its corrupted now. But it has never told you it is and you have no redundancy to correct errors.
Theres many more reasons just copying it is not a good Idea those are just some examples. Theres also Raid soulutions to accommodate mixed drive sizes like Unraid does. And yes it costs money but with Snapraid and Merger FS you can do the same thing for free.
Sure it maybe more effort but the question should be how much is your data worth and are you able to lose it? And what does it cost you to get it back again.