I am looking to add NAS to home network. I place a high value on not losing the files, but would accept a situation in which recovery could take a little time (within reason, assuming cost savings).
I was considering something like a 4-drive NAS (possibly QNAP or Synology) and setting it up for RAID 1. Then, I read an article recommending *not* depending on RAID for redundancy, but instead setting up two NAS units, with one as the primary, which is set up to periodically back up to the other, which acts as a secondary (not seen by network users). The gist of the argument was that the HDD isn't the only thing that can fail, and if a NAS component fails you'll be dead in the water and possibly beyond recovery.
This makes some sense to me, although I was originally (and by default still) of the opinion that the HDD is by far the most likely component to fail, due to the mechanical nature. Not sure what MTBF is on other NAS components, but I expect it's longer than for HDDs.
The only downside I can see to the "fully redundant" argument, off the top of my head, is that I will probably spend more for two 2-drive NASes (setup as RAID 0) of equal performance to a single 4-drive NAS. Although, the secondary unit in the two-NAS solution could be lower-performance and I probably wouldn't even notice it, so I could save a little $ there. I could probably even scrimp a little and go with one of the very low-end consumer units and be okay.
Thoughts/opinions/considerations/experience on this? I appreciate any wisdom you can share.
Because I am religious about backups I've never lost data to hard drive failure. But I have been the victim of theft. For this and other reasons I strongly believe that the best data protection strategy is to make backups to media that is taken offline and have a rotation scheme that keeps at least one backup offsite.
I use bare drives that plug into a USB 3.0 dock - so there's no incremental cost for more backups beyond the raw storage. The drives fit into my bank's safety deposit box and I rotate a fresh set of backups there once a month.
I have a 2TB NAS that uses RAID5
That way a single drive failure does not compromise the data.
Best option in my opinion
Well - it (mostly) protects you from drive failure but it doesn't do a thing for you if you accidentally delete files, suffer corruption due to viruses or other glitches, have the RAID system itself die, have your computer stolen, etc. etc.