ST8000AS0002 Seagate Archive 8TB: It's SMR, Here's What That Means
The ST8000AS0002 is a Seagate Archive HDD 8TB, and it is the clearest example of a drive that is excellent for one job and dangerous for another. It is SMR. This covers what that means and where it belongs.
What is the Seagate ST8000AS0002?
A 3.5 inch, 8TB, SATA 6Gb/s drive from Seagate’s Archive HDD line. 5900 RPM class, shingled magnetic recording (SMR), built for write-once, read-many archive workloads at the lowest cost per terabyte of its era.
It was one of the first high-capacity SMR drives sold widely, and it is the reason many people learned what SMR means the hard way.
Why is the ST8000AS0002 SMR, and why does it matter?
SMR overlaps tracks to fit more data per platter, which is how this drive reached 8TB cheaply. The cost is that rewriting data means rewriting every overlapping track, which is slow. Our SMR vs CMR guide covers the mechanism.
The consequence: fine for sequential writes and reads, poor at random writes, and unsuitable for any array. A RAID rebuild onto this drive can slow so much that the controller drops it as failed.
Where the ST8000AS0002 is actually fine
Being fair, because it does its intended job well.
Single-drive archive where data is written once in large sequential blocks and rarely rewritten.
Cold backup targets receiving sequential backup streams, where the backup software does not do random writes for indexing.
Media libraries written once and read many times.
In those roles it delivers 8TB for less than any CMR drive of its generation.
Where it must not go
Any RAID array. Any NAS with multiple drives. ZFS or similar. Any workload with random writes — databases, virtual machines, file servers with many users.
People put these in NAS units because they were cheap, and the failures came months later during a rebuild. Our drive class guide covers what a NAS actually needs.
What to buy instead for an array
A CMR drive at the same capacity. The Seagate Exos 7E8 or IronWolf at 8TB, the Toshiba MG08, or the WD Ultrastar HC320 all deliver 8TB CMR. Our Ultrastar 8TB guide and MG08 8TB guide cover two of them.
If you already have one
Three practical points.
In an array: replace it with CMR before the next rebuild, not after.
In a single-drive archive: keep it, it is doing its job.
Buying used: only for archive, and check hours and health data. Our hours guide covers judging them.
Frequently asked questions
Is the ST8000AS0002 SMR?
Yes. It is a shingled magnetic recording drive, built for write-once archive workloads. Poor at random writes and unsuitable for any array.
Can I use the ST8000AS0002 in a NAS?
No. In a multi-drive NAS or RAID, random writes collapse performance and a rebuild onto this drive can fail. Use a CMR drive.
What is the Seagate Archive HDD good for?
Single-drive archive, cold backup targets receiving sequential streams, and media libraries written once and read many times. It delivers 8TB cheaply in those roles.
Why is my ST8000AS0002 so slow?
Random writes. Once the drive’s buffer fills, it must rewrite overlapping tracks, which is very slow. Sequential writes and reads are largely unaffected.
What should I buy instead for RAID?
A CMR drive at the same capacity: Exos 7E8, IronWolf, Toshiba MG08 or WD Ultrastar HC320 at 8TB.
I already have one in an array. What should I do?
Replace it with a CMR drive before the next rebuild, not after. The failure happens during rebuild.
Seagate Archive HDD (SMR)
ST8000AS0002 8TB SATA Archive Hard Drive
Tell us the workload. If it is an array, we will quote a CMR drive instead and explain why.
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