Look, I completely understand why you're looking through online auction houses and decommissioned server parts sites for ex-enterprise SSDs for your home lab. SSDs are expensive enough when buying consumer-grade ones — never mind when you're looking for high endurance models to stuff servers full of. And since these drives have been used, refurbished, and resold, you want to know that their SMART health data is good to go.

Which is fine, an abundance of caution when using the secondary market is wise. And with hard drives being faked, SSDs are even easier to make seem like they're bigger or healthier than they really are. So, what can the SMART data on that refurbished SSD tell you, and what is it hiding under a false sense of security when it comes back with a clean bill of health? Let's talk firmware, monitoring, and a little bit of data health.

What doesn't get picked up by SMART data

That enterprise SSD could be hiding a multitude of data storage sins

Hi, XDA's resident datahoarder here, owner of so many SSDs and hard drives of varying provenance. While SMART attributes could potentially warn of impending data doom, the absolute truth is that SSDs, even enterprise ones, can fail at any time. That's why we spend so much time reminding you, dear reader, that the 3-2-1 backup rule isn't an optional suggestion.

And even if you can read reallocated sector count, erase fail count, uncorrectable sector count, and other pertinent SMART data logs, there are a ton of other things not logged in that database. SSDs use wear-leveling algorithms to ensure the drive's longevity matches the total bytes written (TBW) count—bad algorithm, bad drive, etc, etc. SMART data won't measure if that algo has your new-to-you SSD pegged for an untimely death thanks to uneven wear distribution.

Nor will it log issues with over-provisioning or spare block depletion. Sometimes, the manufacturer's own tools can give you this crucial data, but you also can't assume that any stored data in a refurbished drive controller is accurate. And while consumer SSDs often have fewer than 10% of extra NAND cells for over-provisioning, enterprise SSDs heavily rely on them for endurance, and could have up to 28% or more. If the over-provisioned NAND has already been used up, that ex-enterprise SSD could be a time bomb for your data security.

Other things that might be wrong and not stored in SMART could be thermal damage from overheating, causing NAND flash wear at accelerated rates. And even the data SMART does store could be inaccurate, as many manufacturers allow a certain threshold of reallocated sectors before they're logged in the SMART database. By the time any data is logged, that drive could have experienced any level of pre-existing damage.

The picture is even murkier with dishonest sellers

I'm sure by now you know that flash-based storage is often faked. That's for brand-new, in-box storage sold by unsuspecting big box stores, so you can imagine how pervasive the issue is with refurbished drives on the secondary market. Everything on that drive could be faked, from the firmware reporting significantly higher capacity to what's actually available, to SMART data that's wiped or manipulated to make it seem in perfect health, and because SSDs have no moving parts, putting a worn-out PCB inside a new shell is another way to make that drive look in better condition than it is.

I'm not saying this will happen to you. Well, I'm not, but statistically speaking it will happen, and I speak from experience with dozens of USB drives in my purchase history that came doctored to seem larger than they were.

What to look out for so you don't get burned

As always, if it looks too good to be true it probably is

While looking at the SMART data, remember this is a refurbished SSD. It should look like one in the logs, which will mean some wear and tear. If the power-on hours value is blank or any of the SMART values look too perfect, it's been tampered with. The manufacturer's app should pick up the firmware on the drive, and it should show a firmware version number that corresponds with an official one.

Check the write endurance remaining value, and see if it feels right compared to the power-on hours. More power-on hours, fewer endurance remaining, and it should be a fairly even match. Even things like the temperature sensor could be tampered with, so run some benchmarks to get it heated up and see if it changes and makes sense based on other SSDs you've used. And of course, if the price is too good to be true based on the capacity, condition, or form factor, don't buy it.

Use official tools to verify everything

Every large SSD manufacturer will have a drive checking and verification tool that you can install, test the drive, and check firmware validity along with other information. My advice? Use them. Use them as soon as you receive the refurbished enterprise SSDs, so that if you have issues, you're in time to use your credit card's chargeback facility if the seller isn't allowing their return. Use multiple tools and check each output so you are sure of the readings. It's not out of the realm of possibility that the firmware is faked to appear only correctly with the manufacturer's tool.

This is one of the only situations where I think chargebacks are warranted. Most of the time, they make things worse for the other credit card users, but it's the only way to deal with dishonest sellers who won't follow regular grievance or return processes.

SMART data is a helpful tool but it's only part of the picture

You might think you're being smart by ordering refurbished ex-enterprise SSDs, but the sad truth is that many of the drives on the market are gray market fakes or doctored somehow to seem like they're healthier, larger, or other features. SMART data might show some useful information, but it's incomplete and doesn't measure other potentially devastating data points that you'd want to know about. Stick to reputable large resellers and you're probably fine, but as always, buyer beware when ordering refurbs.