SSDs and SMART Data

By Henry Newman

One of our customers wanted to know if the SSDs they purchased were using going to fail. They were concerned that the SSDs had used up their write budget (all NAND SSDs are over-previsioned as cells fail after a certain number of writes).

I asked someone to collect the SMART data for the SSDs in question, only to find that the information could not be interpreted. So we contacted the “major” hardware vendor who sold the systems.

They had no idea how to interpret the SMART information on the SSD they sold us. To add insult to injury, the senior technical people from the vendor told us that we had to buy SLC SSDs, as they do not wear out like MLC SSDs.

I could not believe my ears and told them they were just wrong. They held their ground, and then I realized why. This vendor only sold enterprise SSDs that were SLC. Please note that SLC NAND is falling out of favor by the vendors that make the NAND, which is one of the reasons I told this vendor they were wrong.

So what did I learn from this little encounter? The first thing I learned is that at least this hardware vendor’s senior technical staff—even the very senior ones—are not well versed on technologies other than the ones they sell. I am not sure if this applies to all hardware vendors or not, but it sounds to me like the company line is “if we do not sell it we do not have to learn about it.”

The second thing I learned is that SMART data collection for SSDs it not obvious. The information passed back is not easily interpreted. At least for the SSDs this customer had, the hardware vendor had no information. We went to the SSD vendor website and the documentation was non-existent—likely because it has NDA information in it. This is totally different than disk drives as you can get everything you want from Seagate’s website.

This article was originally published on August 09, 2013