I know many years ago there was a "school of thought" that you should mix up your data drive manufacturers and not lean on the same hdd for every data drive. I somewhat understood the logic, but I'm wondering if that "school of thought" has possibly dwindled down at all?

The reason I'm asking is because over the years I've become very fond of a Seagate NAS drive (https://www.amazon.com/dp/B084ZV8YW8?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1) with a 5-year warranty on them. They seem fast, I haven't had one fail yet, and they run cool. You can certainly pay less for another drive, but I feel this is sort of an area where you get what you pay for.

So, as I need to replace drives now and upgrade size, does this "school of thought" still exist and I should deviate away from this drive or is there really no harm done nowadays in piling up on one drive?

Edited December 13, 2025Dec 13 by JP
Typo

I would think that the biggest similar criteria is not to buy multiple identical drives at the same time as then if one is faulty there is an increased likelihood of the others being from the same batch and also faulty,

Just now, itimpi said:

I would think that the biggest similar criteria is not to buy multiple identical drives at the same time as then if one is faulty there is an increased likelihood of the others being from the same batch and also faulty,

Understood. But in my case this isn't what is happening. I bought one of these drives 4 years ago. Another 2 years ago. Now looking to buy another now. Basically, that is one risk I don't have.

I think originally this school of thought surfaced because if there was a conflict between Unraid and a specific drive, your problem was only segregated to a small subset of drive(s) on the array instead of it being all of the array. Again, I understand the logic in that, but when I've successfully used the same drive for 4 years now, it feels like that risk has been lowered at least some, but again, not certain about that and is why I'm asking.

I've also not kept up with the new builds people put together nowadays. Do they care about this type of thing or are they just buying all the same drives? Back when I first built my Unraid server (can't even remember how long ago that was, 15 years?, crazy), this school of thought seemed pretty significant, so I made a point to have a huge diversity amongst my drives. No two drives were the same. Again, just wondering if this is something people are really concerned at all about now. Not sure myself.

Edited December 13, 2025Dec 13 by JP
Typo

I'm a Seagate guy, Exos more specifically. Beyond Itimpi's example of a problem batch, I see no reason to vary the drive manufacturers or models.

I think many people have a ‘preferred’ supplier while others could not care. I think any strong preference is often arising from some past experience with a particular supplier. I for instance like Seagate drives and find them amongst best value for money and they have proved reliable for me.. Others have stated they have had problems with Seagate drives and thus avoid them.

Thanks everyone. I'm sensing that amongst even the two of you (experts), this sort of diversity is not something to put a great deal of emphasis on. It seems as though if you have personal preference, it can outweigh the need for any need for diversity (outside of the exception Itimpi mentioned, which isn't my case). Thanks again. I'll buy what I like.

Edited December 13, 2025Dec 13 by JP
Typo

I don't think anyone is truly making a 'bad' drive these days and your chance of getting one that goes belly up is purely a matter of 'luck of the draw'. You can see BackBlaze drive data report here (Be sure tor ead the sections where they discuss the outliers with high failure rates!) :

https://www.backblaze.com/blog/backblaze-drive-stats-for-q3-2025/

In any case, if there were to be some design (or manufacturing) change that would result in a statistically greater number of defective drives in one model, by the time it was (most) likely discovered, it would already be superseded by a newer version which probably would not have the same problem. I generally purchase a new drive during a sales event and shop for the best price. I do want a NAS 'branded' drive because there is some reason to think the drive firmware is optimized for NAS operations. Whether this makes any difference for use in my Unraid server is really an unknown. Perhaps, I am just kidding my self...

Frank makes some valid points. Hard drive design and manufacturing is much better and mature than during the Maxtor and Deathstar days.

The diversity strategy might still make sense if you are building a data center and buying hundreds (thousands?) of drives at once. High availability and avoiding single points of failure then are key considerations in a commercial environment. For the majority of Unraid users, the sample size of drives in your server really doesn't make a difference. May actually make things easier, as you would only need to deal with one company for RMA, not several different ones.

10 minutes ago, ConnerVT said:

May actually make things easier, as you would only need to deal with one company for RMA, not several different ones.

One other thing to think about is deciding on a single drive capacity with a long term perspective. I have currently settled on 12TB for my systems. I have two 12TB drives residing in my storage area awaiting the day when I might need more capacity or have a drive fail.