Orion: UFS vs ZFS testing questions

From: Michael Schmitt <mschmitt_at_uchicago.edu>
Date: Wed, 5 Mar 2008 10:47:16 -0600
Message-ID: <48E3A2F3F665464384887BA27428983E02A8CEC9@EVS01.ad.uchicago.edu>


Hi all,  

I have some questions about testing I did using the Orion tool against UFS and ZFS. We found that UFS was giving us better IOps results for small IO, while ZFS was giving us better MBps for large sequential IO. I was hoping that the list can help me figure out why. First, are there any issues using Orion to test these file systems?   

Test setup:

I attached the same SAN Lun to a Solaris 10 server as either a UFS or ZFS mount point. I was told that both file systems were setup using an 8K block size. I created two 5G files on the file system, and ran the following Orion command  

orion_solaris64_sparc -run simple -testname <test_name> -num_disks 4 (<- I just picked a random number here)  


A sample section of the results are listed below. We found that the UFS system was giving us 722 IOps using 8k small random IOs, while the ZFS system was giving us 361 IOps for the same test. We found almost the opposite results for 1M large sequential IO. The results showed that we were getting 35.33 MBps using UFS, and 84.04 MBps using ZFS.  

Since we used the same SAN Lun for both tests, the only difference between these two tests that I can think of is which file system we used. Can anyone give me any advice on what we might be doing wrong, or help to explain the results we are seeing?  

Thanks in advance        

UFS: Point 4 (small=3, large=0) of 29

ran (small): Index = 3 Count = 10850 Avg Lat = 5.53

ran (small): my 4 oth 0 iops 722 size 8 K lat 5.54 ms bw = 5.65 MBps dur 59.94 s READ  

Point 24 (small=0, large=3) of 29

ran (large): Index = 3 Count = 527 Avg Lat = 113.34

ran (large): my 4 oth 0 iops 35 size 1024 K lat 113.22 ms bw = 35.33 MBps dur 59.73 s READ    

ZFS: Point 4 (small=3, large=0) of 29

ran (small): Index = 3 Count = 5431 Avg Lat = 11.04

ran (small): my 4 oth 0 iops 361 size 8 K lat 11.07 ms bw = 2.82 MBps dur 59.94 s READ  

Point 24 (small=0, large=3) of 29

ran (large): Index = 3 Count = 1249 Avg Lat = 47.89

ran (large): my 4 oth 0 iops 84 size 1024 K lat 47.59 ms bw = 84.04 MBps dur 59.84 s READ

Received on Wed Mar 05 2008 - 10:47:16 CST

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