As you should, say for example your array's max performance was 300MB/s. This is a maximum of 300*1024*1024 = 314,572,800 B. Therefore if you test with a 256KB (262144 B) block size then you will see 1200 IOPS whereas if you test it with 4KB block size then you will see 76,800 IOPS and again if you test it with 0.5KB block size then you will see 614,400 IOPS. Granted there is some overhead and it generally doesn't scale 100% lineally and depending on workload and current array you may want to test at different block size. For example with SQL server you will likely want to test at either 8KB or 64KB.robnicholson wrote:Actually, I'm not a big fan of IOPS either as using IOMeter, I was able to get wildly varying values on our existing SAN just by modifying the block size.
Generally speaking most websites/tech blogs/SSD manufactors/array manufactours report IO at a 4KB blocksize which is what CrystalDiskMark uses.
Are these numbers from a StarWind cluster? If so what specs i.e. number of HDD, type of HDD (e.g. 1.2TB 10k 2.5 sas), RAM cache size, SSD cache, flat or LSFS?robnicholson wrote: -----------------------------------------------------------------------
CrystalDiskMark 3.0.2 x64 (C) 2007-2013 hiyohiyo
Crystal Dew World : [ ... ]
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]
Sequential Read : 280.706 MB/s
Sequential Write : 221.522 MB/s
Random Read 512KB : 179.140 MB/s
Random Write 512KB : 130.066 MB/s
Random Read 4KB (QD=1) : 18.603 MB/s [ 4541.8 IOPS]
Random Write 4KB (QD=1) : 12.230 MB/s [ 2985.8 IOPS]
Random Read 4KB (QD=32) : 231.564 MB/s [ 56534.1 IOPS]
Random Write 4KB (QD=32) : 105.039 MB/s [ 25644.2 IOPS]
Test : 1000 MB [E: 0.9% (0.1/10.0 GB)] (x5)
Date : 2014/08/22 14:55:02
OS : Windows Server 2012 Datacenter Edition (Full installation) [6.2 Build 9200] (x64)
I totally agree that just reporting IOPS numbers isn't that helpfful but combined with the information around your specific setup it is most certainly interesting. Ideally it would be inside the CSV as that is where StarWind does it's magic and where you will see the benefits from the additional features such as the RAM cache etc.upgraders wrote:Well still not clear to what you would like me to test. To test the CSV (which would be a true test of the Starwind system) I would need to mount the CSV as a drive and run it. Is that what you want?
Here are the results running on the RAID 0 drive directly for all three nodes. Node 1 and 2 right now are partner Nodes. Node3 is "Dormant" at the moment. It is not being used a a partner Sync. (Some issues I am waiting on with Starwind before connecting) so basically very low load.
Thanks
Jason
I agree that a raw file copy or something like that would be better and more real world. I think it would also be best if you then timed a copy of that copy or a secondary copy of the first as this will help show the benefits of StarWind as well.