Data Hoarder

Same reason why people prefer getting a new car to a used car: you don't know the care and maintenance, or wear and tear, the previous owner maintained. You could end up saving money... Or you might end up buying a junker.

I feel like the hard drive should be self evident, but I wouldn't hate a used SSD so long as it's a modern drive for a discount. With SSD prices always falling it would need to be compelling though.

I think this kind of conversation always needs to highlight the use case/cost. Like, if you just want to cache some content that you could re-download, aren't attached too emotionally, and get a used hard drive for a steep discount? I'd say go for it. Especially since there are generally better chances of indicating failure with hdds.

SsDs have an annoying habit of just dying, at least on me. No warning and no chance of recovering data. Maybe there a good use case out there where you would be willing to run that risk, especially if they are cheap enough, but most of the ones I can think of I'd just grab a new drive anyway, would have to be a hell of a discount .

Imo buying used hard drives is worth the savings. Never had any problems.

Flash technology used in SSDs has a limited lifetime in terms of writes per location. Although SSDs have the intrinsic feature of wear leveling to attempt to spread out those writes across all locations in the device, eventually one or more locations will wear out and no longer accept data.

As there is no easy way to determine how many write cycles have occurred in an SSD prior to purchase, there is always a risk of getting a device that starts failing the day after one installs it.

Lifespan already got eaten up. Higher rate of data loss.

ServerPartDeals has good reputation. I've been using used hard drives for years; used to only purchase new, but changed my opinion after trying some used enterprise drives. Also have a few used SSD's that work fine.

Cheers!

Depends on the use case

It’s not

I built my first TrueNAS box using new old stock drives from eBay. Immediately after they arrived I learned SMART can be wiped, so I carefully inspected the drives for physical signs of use. Fingerprints, scuff marks, wear in the screw holes, insertion marks on the pins, that kind of stuff. They had none of those, fortunately, but the sealed anti-static bag had some weird half-English instructions that seemed extremely subpar for Western Digital.

So after careful inspection, all I could really guarantee was ... nothing. They appeared to be unused and the SMART was cleared. So far they've worked well.

But I just didn't sleep well trusting my data to them, so I purchased a set of new drives this week. These old drives are going into a tertiary local backup DAS where they'll be a last resort after my main external drive and cloud backups. They won't be a total loss, but I also won't be relying on them for anything.

I think the biggest problem is that you don't know what you are really getting.  

Mechanical drives do wear down over time, but you can get a solid 5+ years of use out of them. However, SSDs are much worse. They have a specific number of writes and they will start failing. This means... if it was used in data center as cashing or temporary memory... that drive is TOASTED!  

The next problem is that... people who sell the most drives are typically those who use them the most. A small data center, school, company, and so on. They are the ones who have 50+ drives to replace and often times they will sell the old ones. This means you are far more likely to get a drive that has more ware on it than one that doesn't.  

There are some things you can do if you are dead set on buying a used drive.

• Mechanical Drives - Mechanical Drives typically last longer than SSDs and they are normally cheaper so you are out less money in the worse case situation.
• John Doe - Buy from someone local as they are less likely to have heavily used that drive.
• Photo - Ask for a photo of the drive. If the drive was made in 2001 it probably has some extra wear and tear. This also allows you to double check that the drive and post is the same. Some of these companies will have a random receptionist make the ebay post who might not know anything about a harddrive and could unintentionally use wrong information misleading you.  

Because of quite high chance of getting an SSD that was overwritten multiple times or an HDD that was used a lot which increases chances of it's soon failure. But again, used drives might not be bad if you're buying from a reputable seller and depending on what you use them for.