Hi Suresh,
has your server installed a HP SmartArray P400 array controller? This controller has 256 or (what I believe) 512 MB battery buffered cache. Testing with a 100 MB file will result in Testing SA P400 cache response time. Testing with a 1 GB file will still result in 50 % SA P400 cache response time.
My experience is that a FC connected Filer will not reach throughput of a SA P400 cache while testing with small file sizes. But you may try your tests with much more data. Let's say 10 processes in parallel with 1 GB each. You may also write more data to your filer than your filer has memory installed (= 16 GB) to see it's memory to disk write speed.
But for all this the two questions are: What do you want to benchmark? and: Is this reflecting your workload?
Best Regards
i. A. Dipl.-Inform. (FH) Walter J. Kießl
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Von: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] Im Auftrag von Suresh Rajagopalan Gesendet: Montag, 22. März 2010 00:51 An: tnaple@BERKCOM.com Cc: toasters@mathworks.com Betreff: Re: I/O benchmarking
Here are some numbers from crystaldiskmark. On crystaldiskmark the max file size is 1000Mb. The host has 64G of RAM and 8 six-core processors.
1. DL785G6, 100Mb file local disk
a. Seq Read 216.5MB/sec Write 78.4MB/sec
b. Random 512k Read 58.14MB/sec Write 301.9MB/sec
c. Random 4k Read 26.2MB/sec Write 41.3MB/sec
2. DL785G6 100MB file on Filer LUN (NTFS)
a. Seq Read 175.1MB/sec Write 100.7MB/sec
b. Random 512k Read 103.7MB/sec Write 71.44MB/sec
c. Random 4k Read 15.7MB/sec Write 7.6MB/sec
3. DL785G6 1000MB file on local disk
a. Seq Read 236.8MB/sec Write 92.7MB/sec
b. Random 512k Read 49.71MB/sec Write 217.2MB/sec
c. Random 4k Read 1.33MB/sec Write 20.63
4. DL785G6 1000Mb file on filer LUN (NTFS)
a. Seq Read 164MB/sec Write 98.8MB/sec
b. Random 512k Read 101.1MB/sec Write 63.2MB/sec
c. Random 4k Read 13.9MB/sec Write 7.8MB/sec
Suresh
From: Timothy Naple [mailto:tnaple@BERKCOM.com] Sent: Friday, March 19, 2010 9:21 PM To: Suresh Rajagopalan Cc: Toasters List Subject: RE: I/O benchmarking
Suresh,
Performance benchmarking is a science that involves many variables. I am not familiar with CrystalDiskMark but I just downloaded the source for 3.0 RC2 and will have a look to see how applicable it could be to a filer vs local disk comparison. Can you add some more details about your configuration? (any options you run with the test, specs/model of the server including controller/RAID card(s), OS on the server, disk model in the server, disks in the filer, model of the filer, ONTAP rev, etc). A lot of detail is going to be required to make any headway or recommendations for a valid test.
Thank you, Tim
From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Suresh Rajagopalan Sent: Friday, March 19, 2010 8:55 PM To: Toasters List Subject: I/O benchmarking
I'm using the free tool Crystaldiskmark to do some I/O comparison between local disk and our filers. On at least one system (SAN connected), the local disk (6 disks in RAID1) consistently comes out ahead in both read and write. Filer is lightly loaded, and this is on a 56 disk aggregate. I'm kind of stumped on this one, and would like to know if:
a) Are there any other commonly used benchmarks which I can try with the filers?
b) This is on a 2G FC SAN. How much improvement can I expect with 4G or 8G?
Thanks Suresh
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