IOPS - Read vs. Writes in Capacity Planner

[mike01801]

Is there anyway to get a break down of read vs. writes in Capacity Planner. I'm trying to determine the correct amount of spindles (drives) to allocate to the VMs, but I need to know the break down of reads vs writes, so I can calculate the RAID adjusted IOPS.

Also, in the Capacity Planner assessment reports, When it lists the machines, I see a column called "I/O (Trans/sec)", is this an average of every time the collector service collected data from that machine, or some level of percent (like 95% percentile)?

Thanks,

Mike

[skayser]

Mike, did you ever figure out how to get the read vs. write breakdown in CP? As you pointed out, the read/write ratio is really a prerequisite for spindle calculations.

[dconvery]

There is a Storage Summary Report that will give you average IO stats and breaks it down by reads and writes. There are also a few IO and bandwidth reports.

Check out the "Create Customer Performance Disk Bytes/sec Export" report. You can add the following PerfCounters:

Disk Write Bytes/sec and Disk Read Bytes/sec

From what I understand, these reports will give you an average of each hour over the time of the assessment. SO a 30 day assessment will average 30 counters for each hour (0-23). Its hard to explain. If you look at hour 3, for example, it is the average of all of the hour 3 samples for the 30 days of the assessment. add all of the captures and divide by 30.

Hope this helps.

Dave

[skayser]

Dave, thanks a bunch! The custom reports were exactly what I was looking for. Via "Disk Reads/sec" and "Disk Writes/sec" I can put together the IOPS figures that we need. Would be helpful to also have the time at which "Max observed" was observed, but for a start, the averages will do.

[jimlawrnc]

where did you find the custonm reports? 

[dconvery]

Reports -> Custom Reports

[ianhawke]

I'm kinda new to this, I go inside the custom report and add 2 more fields

PerfCounter

in Criteria? = or Like?

then

Disk Writes/sec

Disk Reads/sec

and

and

is it ok? Cause when I give the ok it doesn't collect any data...?

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Nothing ok, I got it! Nice stuff :smileygrin: