3PAR Users Group

A Storage Administrator Community




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: How to calculate possible maximum IOPs?
PostPosted: Tue Mar 13, 2018 12:58 pm 

Joined: Wed Nov 08, 2017 8:57 am
Posts: 25
I have a 7200 with 36 total drives..

(8) 100 GB SSD
(28) 900 GB 10K FC (150 IOPs per disk?)

This is used soley for VMware and VDI.. I'm trying to find out if I have enough of the right type of disk for a new environment I am building..

How can I calculate total possible IOPs? Right now I have 41 RAID5 VVs on on my FC disks.. I'm guessing it's not as simple as 28 disks * 150 IOPs per disk = 4,200 Maximum IOPS for volumes that reside on the 10K FC, is it?

Thanks for any replies..


Top
 Profile  
Reply with quote  
 Post subject: Re: How to calculate possible maximum IOPs?
PostPosted: Tue Mar 13, 2018 1:30 pm 

Joined: Mon Sep 21, 2015 2:11 pm
Posts: 717
Location: Europe
You are right. It is no that simple.

Your FC drives are able to provide on average that backend performance.. Given that each IO is on average 1/2 a rotation away on the platter. If you have sequential you get more IOPS, if you need to rotate more than 1/2 platter on average it will be less....

But this is only a small fraction of the total picture... Each R5 write IO will produce 4 backend IO... On R6 it is somewhere between 6 and 7.

On the positive side you have cache, where a cache hit is a backend IO you don't have to do.... And with SSDs, I'm assuming AO which bring the effectiveness of that into the picture.

So my best suggestion is either to look at what you're doing today (frontend IOPS), look at %busy on backend (disks) and assume that the new dat is like the current data and do those numbers.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 


Who is online

Users browsing this forum: Google [Bot] and 9 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group | DVGFX2 by: Matt