Hi everyone. I posted this on the OmniOS list as well, but hoping
someone here can help.
We are running our final tests with our servers before we send them
off to the DC. We have tested various ZIL devices, including Zeusram
and DDRdrive. I wanted to get some comments on what we should expect
when it comes to w/s in iostat for the ZIL. I've heard conflicting
So far, running gnu dd with 512b and oflag=sync, the most we can get is 8k
iops on the zil device. I even tried with some SSDs (Crucial M4,
Vertex 4) and it is the same result. They all cap at about 8k iops.
The only outlier is the DDRDrive, which hovers around 6.9k iops. To
rule things out, I tried Nexenta, OmniOS and Solaris 11, all with
mostly the same result. In addition to the log device, the pool is
made up of 6 mirrored pairs of 2TB Western Digital drives. No cache
devices added yet.
Is this the expected result? Should I be pushing for more? In IRC I
was told that I should be able to get 12k no problem. We are running
NFS in a heavily used environment with millions of very small files,
so low latency counts.
In case it helps, the hardware is a Supermicro chassis (24 disks),
X9-DRi-F motherboard, and LSI 9211-8i connected to the SM backplane.
Networking is 10gbe (x510-DA2) directly connected via SFP+ twin-axial.
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