Hi,
We have a Nautilus (14.2.9) Ceph cluster with two types of HDDs:
- TOSHIBA MG07ACA14TE [1]
- HGST HUH721212ALE604 [2]
They're all bluestore OSDs with no separate DB+WAL and part of the same pool.
We noticed that while the HGST OSDs have a commit latency of about 15ms, the Toshiba OSDs
hover around 150ms (these values come from the `ceph_osd_commit_latency_ms` metric in
Prometheus).
On paper, it seems like those drives have very similar specs, so it's not clear to me
why we're seeing such a large difference when it comes to commit latency.
Has anyone had any experience with those Toshiba drives? Or looking at the specs, do you
spot anything suspicious?
And if you're running a Ceph cluster with various disk brands/models, have you ever
noticed some of them standing out when looking at `ceph_osd_commit_latency_ms`?
Thanks in advance for your feedback.
Cheers,
--
Ben
[1]:
https://toshiba.semicon-storage.com/content/dam/toshiba-ss/asia-pacific/doc…
[2]:
https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/p…