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Round Robin IOPS Limit
Posted: Wed Apr 29, 2015 6:35 pm
by mphilli7823
Does anyone know if it's best practice with Starwinds to adjust the default IOPS limit from 1000 to 1 in ESXi?
http://kb.vmware.com/selfservice/micros ... Id=2069356
Re: Round Robin IOPS Limit
Posted: Thu Apr 30, 2015 10:21 pm
by mphilli7823
wow no input....
Re: Round Robin IOPS Limit
Posted: Fri May 01, 2015 9:16 am
by lohelle
I have always used 10 (and not 1). No special reason other than thinking it could be a little easier for the hosts and SAN?
Re: Round Robin IOPS Limit
Posted: Fri May 01, 2015 10:56 am
by anton (staff)
Sorry all ninjas are busy
General rule of thumb is faster CPU and storage back end you have smaller threshold value for path switch you set. 1,000 is definitely on a higher side and 1 exhausts system (especially hyper-converged setup...) so give a try to something within 10-100 range on your hardware. Your mileage may vary (c) ...
Good luck!
mphilli7823 wrote:wow no input....
Re: Round Robin IOPS Limit
Posted: Fri May 01, 2015 2:47 pm
by mphilli7823
Cool...I'll change the values and do some testing and report what I find here...thanks!
Re: Round Robin IOPS Limit
Posted: Fri May 01, 2015 2:51 pm
by anton (staff)
Yup! Some sort of a table with numbers would be nice
mphilli7823 wrote:Cool...I'll change the values and do some testing and report what I find here...thanks!
Re: Round Robin IOPS Limit
Posted: Sat May 02, 2015 10:40 am
by craggy
We always do round robin by bytes instead of IOPs and set it to 8972 so we can get maximum utilisation of each jumbo packet before the path switches.
Re: Round Robin IOPS Limit
Posted: Sat May 02, 2015 4:57 pm
by anton (staff)
Did you run any CPU and bandwidth tests to come up with a value?
craggy wrote:We always do round robin by bytes instead of IOPs and set it to 8972 so we can get maximum utilisation of each jumbo packet before the path switches.
Re: Round Robin IOPS Limit
Posted: Mon May 04, 2015 1:24 am
by mphilli7823
Below is a screen shot of the results of my testing.
Test Setup
Test VM = Server 2008 R2, 8 vcpus, 16GB RAM, 40GB Drive
Hypervisor = ESXi 5.1, each hypervisor host has 2x 10GB nics for storage
Storage = Starwinds 6.0.6399, 2x Nodes 24GB RAM, 2x E5620
Storage network is 10gbit
Each storage node has a DataOn DNS1660D with 40x 600GB SAS drives + 4 100GB SSD as cache(LSI cachecade) connected to a LSI 9286CV-8eCC controller
I tested using PassMark's PerformanceTest 8.0 using the all disk tests. Each test was run twice and the averages were used.
As shown by the graphs the sequential read test was the biggest benefactor of this setting. Going forward I will use the iops=10 setting.
- iops_round_robin.PNG (21.36 KiB) Viewed 13335 times
Re: Round Robin IOPS Limit
Posted: Mon May 04, 2015 11:00 am
by anton (staff)
Wow! That's a very impressive report! Thanks for sharing
Just it case... Do you happen to have matching CPU usage on client and server?