I suspect the behavior of the controller and the behavior of the drive
firmware will end up mattering more than SAS vs SATA. As always it's
best if you can test it first before committing to buying a pile of
them. Historically I have seen SATA drives that have performed well as
far as HDDs go
Dave-
These are just general observations of how SATA drives operate in storage
clusters.
It has been a while since I have run a storage cluster with SATA drives,
but in the past I did notice that SATA drives would drop off the
controllers pretty frequently. Depending on many factors, it may just
Agreed. I think oh …. maybe 15-20 years ago there was often a wider difference
between SAS and SATA drives, but with modern queuing etc. my sense is that
there is less of an advantage. Seek and rotational latency I suspect dwarf
interface differences wrt performance. The HBA may be a bigger
FWIW, those guidelines try to be sort of a one-size-fits-all
recommendation that may not apply to your situation. Typically RBD has
pretty low metadata overhead so you can get away with smaller DB
partitions. 4% should easily be enough. If you are running heavy RGW
write workloads with small
In releases before … Pacific I think, there are certain discrete capacities
that DB will actually utilize: the sum of RocksDB levels. Lots of discussion
in the archives. AIUI in those releases, with a 500 GB BlueStore WAL+DB device,
you’ll with default settings only actually use ~~300 GB most
Anthony,
I had recently found a reference in the Ceph docs that indicated something
like 40GB per TB for WAL+DB space. For a 12TB HDD that comes out to
480GB. If this is no longer the guideline I'd be glad to save a couple
dollars.
-Dave
--
Dave Hall
Binghamton University
kdh...@binghamton.edu
Mark,
We are running a mix of RGW, RDB, and CephFS. Our CephFS is pretty big,
but we're moving a lot of it to RGW. What prompted me to go looking for a
guideline was a high frequency of Spillover warnings as our cluster filled
up past the 50% mark. That was with 14.2.9, I think. I understand t
