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CIFS IOmeter results
Hello,
Can anyone please explain me exactly what the IOmeter results mean or how to interpret?
I have attached screenshot of the results that I have ran on;
1) CIFS File system
2) Existing on RAID6 NL-SAS
Created a File Share on the above File System > Mapped it to Windows machine from where I ran IOmeter
Ran against 512 kb with 70 % Read & 30 % Write ratio.
Difficulty is how shall I interpret results that IOmeter is showing;
Is it like below?
1) IOPs: 183.23 = 187.82 * (total disks in RAID 6 where my CIFS share exist) = 187.82 * 8 = ~ 1500 IOPs
So is my current RAID 6 capable of handling ~ 1500 IOPs ?
2) MBpS: 96.07
So is my current RAID 6 CIFS Pool capable of handling ~ 96 MBpS of traffic?
3) Latency: 5.45 ms
So my current RAID 6 can handle ~ 5.45 ms of latency, not below that?
I want to know by this test, taking into consideration above File size and read/write ratio;
1) How much max IOPs my CIFS share can handle ?
2) What is the worst latency ?
3) Maximum Bandwidth CIFS share can handle ?
Please help.
Thanks.
sluetze
300 Posts
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June 25th, 2015 23:00
1) IOPs: 183.23 = 187.82 * (total disks in RAID 6 where my CIFS share exist) = 187.82 * 8 = ~ 1500 IOPs
So is my current RAID 6 capable of handling ~ 1500 IOPs ?
--> no. This is already the number of IOPS your RAID6 could handle in this specific test. This may vary when you modify the blocksize in your test.
2) MBpS: 96.07
So is my current RAID 6 CIFS Pool capable of handling ~ 96 MBpS of traffic?
--> your RAID6 CIFS Pool in this Test-configuration was able to Handle 96MBpS. This can / could be limited by Network bandwidth available for your test. (you will get lower results with 100MBit/s network than 1GBit/s network or 10GBit/s network) this may also vary with the blocksize configured in the test.
3) Latency: 5.45 ms
So my current RAID 6 can handle ~ 5.45 ms of latency, not below that?
--> the average latency in this test was 5.45. Average means there were values above and below that.
I want to know by this test, taking into consideration above File size and read/write ratio;
1) How much max IOPs my CIFS share can handle ?
depends on the blocksize of your test.
2) What is the worst latency ?
-> see "maximum latency" in your results.
3) Maximum Bandwidth CIFS share can handle ?
--> you mean throughput and this has some dependencies.
before using iometer you should think about what your workload is and how it "talks" to your storage. use this values to define a test to get valid results.
SunshineM
119 Posts
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June 25th, 2015 23:00
Awaiting reply from anyone please.
Thanks
SunshineM
119 Posts
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June 26th, 2015 02:00
Thanks very much. I am going in write direction to understand this.
Ok, blocksize I took was 512 KB with 70 - 30 % Read - Write Ratio. This is what you meant?
If yes, then I will try with different block size and read/write ratio.
Again want to confirm, that 183 IOPs is the maximum IOPs generated taking into consideration above block size, on the share?
thanks.
sluetze
300 Posts
1
June 26th, 2015 03:00
also take a look on this link which may help you
http://networkadminkb.com/KB/a7/disk-io-tutorial-part-1-basic-concepts-of-disk-io.aspx
sluetze
300 Posts
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June 26th, 2015 03:00
183IOPS was the average value your test showed. no maximum. maximums are also very imprecise (in my opinion)
if you lower the Blocksize you will get higher IOPS. In your Test every IO you send has 512K of data. thus you may saturate your network which limits the amount of data and IOPS you can transfer. If you lower your blocksize you need more IOPS to transfer the same amount of data.
for a 1MB file at 512K you need 2 IOPS
for a 1MB file at 8K you need 128 IOPS
the blocksize depends on the application. Windows Explorer network copies normally use 64K Blocks (depending on some tcp and smb settings).
this is why I said look at your normal workload and try to find a testsetting which matches your workload.
a DNA-Sequenzer uses higher blocksizes (~streaming)
a Database normally uses lower blocksizes
if you have a smb only environment and only use your storage for homedrives and groupdrives I would use 64K as a size to determine my iops.
if you have a specific application take a look in the documentation if there are any values to blocksizes.
sluetze
300 Posts
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June 26th, 2015 05:00
done the math:
1000 IOpS with 512K blocksize each is 500MB/s.
something is wrong with my calculator or with the app vendors requirements.
bhowen
3 Posts
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June 26th, 2015 05:00
is this a simple kb vs KB confusion? maybe they are looking at a 64KB block size... that may fall into a 60-80 MBps.
Rainer_EMC
8.6K Posts
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June 26th, 2015 05:00
Doing a benchmark for IOPS it doesnt make sense to use 512k block size since applications that IOPS bound or sensitive use much smaller block sizes
Similar for thruput – if your app wants highest thruput it uses large block sizes
Bottom line: anyone can run a benchmark – if you don’t know what your workload is and how to interpret its just numbers without meaning
SunshineM
119 Posts
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June 26th, 2015 05:00
Our application requirement (given by that app vendor) will have below;
Host IOPs: ~ 1000
Block Size: 512 kb
Read / Write ratio: 70 / 30
Latency required: below 2 ms
Throughput required: 60 - 80 MB/s
Based on this, I know how to calculate storage design requirements, like RAID group, no. of disks, LUNs etc.
But I want to know if I can use my current RAID 6 Storage Pool having NL-SAS disks to host above application or not?
So I used 512 kb block size with 70 / 30 read/write ratio and generated the results with IOmeter.
Real-time CIFS performance will only tell real time data and not approx maximum capability (which I need to know)
So for that reason, I want to know the approximate maximum capability in terms of IOPs, Throughput, and Latency, the share created on this RAID 6 pool can handle.
Please suggest.
Thanks.
SunshineM
119 Posts
0
June 26th, 2015 06:00
Ok, we cannot argue on the vendor requirements
Main deal here is knowing the maximums, which I am after, so that I can plan future apps also accordingly, If I need to host in this existing RAID 6 pool..
Below are IOmeter results with different values;
SunshineM
119 Posts
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June 26th, 2015 06:00
Awaiting your valuable reply, Sluetze. Please help.
bhowen
3 Posts
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June 26th, 2015 06:00
simply trying to help by adding my 2 cents.
i believe, and i may be mistaken, that 512kb is 64KB.
as sluetze has pointed out, math is broken when trying to squeeze 1000 512KB blocks into 60-80 MB.
looks like the last line of the test hits your target..