Monday, September 18, 2006

Results: file-create

The Test:
30 workstations create a sub-directory, and in that sub-directory create 20,000 files. At each 500 files it does a directory listing and times how long it takes to retrieve the list. A running total of the time taken to create files is kept, and a log of how long each entry takes to create is also kept.
Graph comparing file-create times between OES-Linux and OES-NetWare on an NSS volueThis chart is interesting in several ways. First of all, note the lower error bars for the Linux line. Those bars overlap and up to about 4000 files actually is below the NetWare average. This says to me that when there is CPU room, Linux may be faster than NetWare when responding to file creates. This particular line was caused by the same method as the previous test, namely that some test stations started up to 30 seconds before the whole group was running and therefore had a window of uncontended I/O. Those same workstations finished their tests while others were still around 12000 files, which further explains the downward trend of the Linux line above that threshold.

The second interesting thing is the sheer variability of the results. As with the dir-create test, CPU was completely utilized on the OES-linux box. The reported load-averages were very similar to dir-create. Some test workstations were able to run a complete test before others even got to 12000 files. Yet others took a really long time to process. The file-create test ran well over an hour, where the same test on NetWare took just under 30 minutes.
Graph comparing file enumeration between OES-Linux and OES-NetWareThis graph shows significant differences between the two platforms. As with the first chart, 4000 directories and under some workstations turned in NetWare-equivalent response times when speaking to OES-Linux. As with the above, this was due to uncontended I/O. But once all the clients started running the test the response time for directory enumeration was greatly degraded.

Because file-create seems to clog the I/O channels more than dir-create did, directory enumeration had to compete in the same channels and thus response times suffered. Towards the end of the test when some workstations had finished early response times were creeping back towards parity with OES-NetWare.

Next, create operation differences.


Tags: ,

Labels: ,


Comments: Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?