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2 Iron

## Calculate CIFS Performance

Hello,

How can I calculate current CIFS performance hosted on RAID 6? I need to know throughput and latency.

Using 6 + 2 disks.

Each disk is 2 TB

Thanks

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4 Ruthenium

## Re: Calculate CIFS Performance

EMC has a Rule of Thumb for calculating performance:

15K SAS disk - for small block (less than 32KB) random IO (mix of reads and writes) = 180 IOPS.

So if you take five 15K SAS disks and create a Raid 5 raid group (4+1) - that mean that each disk can handle about 180 IOPS times the 5 disks = 900 IOPS for the raid group. This will provide good performance - less than 20ms for a LUN in that raid group.

This is a rough guideline - response time will increase as the IOPS increase.

If you increase the IO Size, then the IOPS will decrease (inverse relation).

In the "EMC CLARiiON Performance and Availability Release 30 Firmware Update Applied Best Practices.pdf" see page 96 - Random I/O section - this lists the drive type and IOPS.

glen

14 Replies
2 Iron

Thanks,

Mihir

4 Ruthenium

## Re: Calculate CIFS Performance

Not sure I can help you with CIFS performance questions, but take a look at this thread - it has information about determining performance on the Block array using different Raid Types - I attached a couple of White Papers that can help.

IOPs calculation

glen

2 Iron

## Re: Calculate CIFS Performance

I am sorry, but still could not find the answer.

Basically my question is pointing 2 things;

1) Calculate IOPS/Bandwidth for the application that will be hosted on disks. This will be done on various factors, which I found in the guide "EMC CLARiiON Best Practices for Performance..."

But I want answer for below question

2) How to find how much IOPs or Bandwidth (MB/s) current disks or Raid Group is capable of to handle.

In the above guide only there is a table specifying MB/s according to drive type and File size. But that is for single drive.

How to calculate for whole Storage Pool or Raid Group.

Is it like below;

FC 15k rpm for 512 kb file = 32 MB/s

So for RAID 6, it will be 32 MB/s * 8 = 256 MB/s

RAID 6 with 6+2 disks is capable of handling 256 MB/s throughput??

So by this I will be able to find out whether I can host that application in current group or not.

Thanks

5 Rhenium

## Re: Calculate CIFS Performance

There is no simple way to calculate that for NFS/CIFS

Besides IOPS / bandwidth depend on block size, read-write ratio

I would suggest to get in touch with your EMC or partner pre-sales TC who can help you

I you are an EMC partner I would suggest to inquire becoming a member of the the partner USpeed program or to locate on in your company

2 Iron

## Re: Calculate CIFS Performance

I am not including CIFS only, just a general thing for any RAID groups.

2 Iron

## Re: Calculate CIFS Performance

Can anyone please suggest me. I am not after CIFS, but a normal Storage RAID group.

5 Rhenium

## Re: Calculate CIFS Performance

Sure you can just the take usual number of IOPS per disk from the best practices paper and multiply them – but its not going to be matching to a real system performance.

A real system is more complex – you usually use sizing tools and performance papers that are based on actual measurements

2 Iron

## Re: Calculate CIFS Performance

So is this ok;

FC 15k rpm for 512 kb file = 32 MB/s

So for RAID 6, it will be 32 MB/s * 8 = 256 MB/s

RAID 6 with 6+2 disks is capable of handling 256 MB/s throughput??

5 Rhenium

## Re: Calculate CIFS Performance

A couple of pointers:

- RAID write penalty

- write throughput for RAID is different than read

- parity disks don’t help in throughput

- throughput depends on block size

If all you want is some numbers not very meaningful to real life storage systems behavior I suggest to use one the many raid performance calculators on the Internet

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