UNSOLVED
Block Alignment on VMAX All Flash 250F
Hi All,
During performance test with IOmeter, on our VMAX 250F, with 1.5TB of cache, two V-Bricks and 40 SSD disks.
We expected to view 200K IOPS and RT<1ms(Requirements of our RFP). But, when I do the test, we don´t see these numbers.
Only 180K [MAX] IOPS with 1.3/1.4 avg IOPS not sustained.
I noticed a lot of GM consumed, (Topic for another time.) because we created some TDEV´s and I noticed some good variation when we change the Align IO, to 1MB and we saw 290K IOPS and 0.8ms RT sustained.
Changing Align IO/partition Alingment is a good choice for pushing performance and decrease RT?
Thanks in advance.
Hi my friend!
Our environment is based in:
4 ESXi Hosts with 4 VM´s on each host.
2 VM´s with Windows 2012
- 4vCPU;
- 16GB vRAM;
2 VM´s with Linux Red Hat 6.8
- 4vCPU;
- 16GB vRAM;
The 4 virtual machines are acessing disks with RDM and our frame is 80% Full.
One curious point are: When we changing the IO Alingment, we noticed a lot of cache hits, accurately 100% cache hit for 290K IOPS.
And additional info:
IOMeter config schema:
4 workers per VM
288GB of Working set of 9GB in 32 TDEV´s;
8 OiO / 70% Read & 30% Write 8KB Block;
Expected to reach 75% of cache hit!
Thanks!
SKT2
2 Intern
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1340 Posts
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Posted May 5th, 2017 02:00
What is the host OS where the alignment was performed?