ST2000DM008 Seagate BarraCuda 2TB: Why Not for NAS or RAID
The ST2000DM008 is a Seagate BarraCuda 2TB desktop drive, and it turns up in searches from people looking to put it in a NAS or server. This covers what it is, why it does not belong in an array, and what to buy instead.
What is the Seagate ST2000DM008?
A 3.5 inch, 2TB, SATA 6Gb/s desktop hard drive from the BarraCuda family. 7200 RPM class, and this is the important part, shingled magnetic recording (SMR).
It is designed for a single drive in a desktop PC: an operating system, applications and files, with light and intermittent use. In that role it works well and costs very little.
Can I use the ST2000DM008 in a NAS or RAID?
No, and there are two separate reasons.
It is SMR. Shingled recording overlaps tracks, so rewriting data means rewriting overlapping tracks. Random writes collapse in speed once the drive’s buffer fills, and a RAID rebuild onto an SMR drive can slow so much that the controller drops it as failed. Our SMR vs CMR guide covers the mechanism.
It is a desktop drive. Desktop drives retry a bad sector for a long time before giving up. That is correct on a desktop and fatal in an array, because the RAID controller decides the drive has failed and drops it while it is actually fine. Our drive class guide covers the three things that separate desktop, NAS and enterprise drives.
Either reason alone rules it out of an array. Together they make it a bad idea in any multi-drive system.
Where the ST2000DM008 is fine
Being fair to it.
A single drive in a desktop PC. Its intended job.
An external USB drive for occasional file storage.
Secondary bulk storage in a workstation where the data is not critical and there is a backup elsewhere.
In those roles it is cheap and adequate. It is not a bad drive; it is a drive for a specific job.
What to buy instead for a NAS or server
Match the class to the system.
Small NAS: a NAS-class CMR drive such as the Seagate IronWolf. Our IronWolf guide covers the family.
Busy or many-bay NAS: IronWolf Pro or equivalent.
Server or array: an enterprise nearline drive such as the Seagate Exos, Toshiba MG series or WD Ultrastar. Our Exos 4TB guide and Ultrastar guide cover two options.
At 2TB specifically, enterprise drives exist but the cost per terabyte is poor. If you are building storage, a larger enterprise drive is usually better value than several small ones. Our capacity planning guide covers sizing.
I already have one in a NAS. What now?
Replace it with a CMR drive before the next rebuild, not after. The failure mode shows up during rebuild, which is exactly when you need the array to work.
And check what else is in the array. If one SMR desktop drive went in, others may have too. Our drive health guide covers checking what you actually have.
Frequently asked questions
Is the ST2000DM008 SMR?
Yes. It is a shingled magnetic recording desktop drive. That is why it is cheap, and why it does not belong in an array.
Can I use a BarraCuda in a NAS?
No. Two reasons: it is SMR, so rebuilds can fail, and it is a desktop drive whose error recovery behaviour causes the RAID controller to drop it as failed while it is actually fine.
What is the ST2000DM008 good for?
A single drive in a desktop PC, an external USB drive, or secondary bulk storage in a workstation with a backup elsewhere. In those roles it is cheap and adequate.
What should I buy instead for a NAS?
A NAS-class CMR drive such as IronWolf for a small NAS, IronWolf Pro for busy or many-bay units, or an enterprise nearline drive for a server or array.
I already put one in my NAS. What should I do?
Replace it with a CMR drive before the next rebuild, not after. And check what else is in the array, since if one went in, others may have too.
Why is my BarraCuda so slow copying files?
Random writes on an SMR drive. Once the internal buffer fills, the drive must rewrite overlapping tracks, which is very slow. Large sequential copies are much less affected.
If you are sizing storage for a NAS or server, tell us the system and workload and we will quote the right class rather than the cheapest drive.
