I am in the slow process of upgrading five WD 6TB hard drives in my Synology DS1522+ NAS to Seagate 8TB drives. While folks I asked overwhelming say the larger drives (16TB, 20TB, etc.) “have not had any issues,” I am old school and do not want to make that large of a storage jump just yet. For those as data paranoid as I am, some tips:
- Do a low-level format (or “secure erase”) on each new drive first. This will write to every sector, and can catch issues. I have only caught one (or maybe two) drive with issues of the years, but the time spent is worth it to me. I’d rather catch a problem before I install and send them back for a replacement, rather than having an issue show up much later (possibly when the drive is out of warranty).
- Until someone can say that a “20TB” drive is as reliable as a smaller drive, upgrage to the next size up that gives you enough storage. The less dense the data, the safer it “should” be. Also, if a 6TB drive fails, the rebuild time to replace it will be significantly faster than replacing a 20TB drive. And, during the rebuilt time, your data is at risk. I run dual drive redundancy so during the 12 hours my NAS rebuilds, if I have a second drive fail, I am still okay… but if that happens I have no protection from a third failure. Doing 20 hours rebuilds creates a much larger window for data loss if something goes terribly wrong.
- And, of course, make sure anything important is on a backup drive (I use a standalone 10TB just to clone my most important “can’t live without” data), and have an offsite backup of that (I then have that entire drive backed up to a cloud backup service).
If my home burns down, I should at least be able to get back the 10TB of “can’t live without” data from my offsite backup.
Hardware Redundancy is Better
Sadly, Synology units are much more expensive than my Drobos were. My Drobo 5C was $300 retail. I had two that I paid maybe $250 each for. That let me have two 5-bay units for hardware redundancy. This means if a Drobo suddenly died, I still had a second unit with duplicate data (I would sync the two drives). Spending $500 for two 5-drive units was an easier investment than the $1400 it would take for me to buy two DS1522+.
Eventually I do plan to have a duplicate Synology unit. It doesn’t matter what features the device has if one morning it has died. I would have zero access to my data until the unit is replaced or repaired. Having backup hardware is what I prefer.
But I am data paranoid.
How about you? Are you unlucky, like I am, and have had drives “die suddenly” over the years? After that happens enough, the paranoia sets in. I can’t think of a time in the past decades where I didn’t have three backups of everything important ;-)
Same with me. 3 backups or nothing. I once had a sequence of all of them dying but the last one. Scary.
That is terrifying. I would need four, then.
My strong recommendation is to mix different manufacturers and use mirrored drives.
The likelihood of any major manufacturer having quality problem for the drive that you happen to buy is too big to be ignored.
The likelihood of two different major manufacturers having quality problem for the drives that you happen to buy, and then the problem starting to appear at approximately the same time (within the same few months) seems negligible though.
With mirrors rather than for example raid 5 you can always read one disk without any special software/hardware. Also I think it provides the best read speeds, and for most single user applications I think reading happens by far way more often than writing. The exception might be if you are a video content creator or whatnot.
You might lose a tiny amount of space if the sizes don’t match up exactly. If you really want to use every single bit you could probably add a tiny partition that isn’t mirrored, filling the last part of the slightly larger disk.