topic Re: IOPs calc in ONTAP Discussions

IOPs calc

ANILPAWAR1988 — Thu, 05 Jun 2025 06:03:51 GMT

In filer has one aggregate which have 32 disks with Raid DP, I just want to know how much IOPs will generate. 300 GB NetApp disk 1500RPM.

Re: IOPs calc

RAVI_PALADUGU — Mon, 29 Apr 2013 16:23:11 GMT

Hi Anil,

I think this link might help you calculate the IOPS for different type of disks. You haven't provided the type of disk (SATA, SAS, FC...) and so I cannot calculate the IOPS for you.

https://communities.netapp.com/community/netapp-blogs/databases/blog/2011/08/11/formula-to-calculate-iops-per-disk

Best,

Re: IOPs calc

ANILPAWAR1988 — Mon, 29 Apr 2013 16:26:02 GMT

that i have but there nothing mentioned for FC disk...I need details about FC disk..

Re: IOPs calc

RAVI_PALADUGU — Mon, 29 Apr 2013 16:44:54 GMT

There wont be any specific answer that says it can give these many IOPS to answer your question directly. It depends on various criteria's. As a rule of thumb you can say a 15k FC drive can average between 150-190 IOPS.

Remember the IO penalty for RAID-DP is 2.

Re: IOPs calc

johannbell — Wed, 01 May 2013 02:48:37 GMT

Hi Pawar,

You can typically use the SAS figures for FC disks.

Every workload generates different usage patterns, which will be different IOPS figures. IOPS isn't a defined 'thing', so 1000 IOPS for one workload isn't the same as 1000 IOPS for a different workload. Is this all read, all write, some mix? The results will vary a lot.

The reason there isn't a simple figure that you can easily look up, is that there isn't a simple answer.

I work with a rule of thumb of about 2500 IOPS per SAS shelf of 24 disks, and about 1500 for a SATA shelf. A DS14 would be about half of this figure, as it has about half the usable disk count (depending on spares).

Is this a figure you would use as a starting guide to estimate a shelf count for a system? probably.

Is this a figure you would give to a customer as a guarantee and base your designs on it? I wouldn't.

Also keep in mind the huge effect of Flash Cache, Flash Pool and NVRAM in a NetApp. Disk IOPS aren't as important as many people think.