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I am copying a large amount of files from one server to another via robocopy to a UNC share.

I notice that after robocopy completes that there is a large amount of disk activity that lasts for a while afterwards, the server is very sluggish at this time. I suspect this is the Windows' file system caching that is causing the large amount of disk activity after robocopy completes.

For debugging purposes, I would like to see how much data still needs to be written to disk (a performance counter would be best, to see a graph I can cross reference).

I am copying ~110k files that total ~1.3gb from and to Windows Server 2012 R2 instances.

Matthew
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1 Answers1

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For a first look, you can open the task manager and see if the DISK column shows high load.

For a more detailed investigation, you had to use the Performance Monitor application. Follow these steps:

  • open it

  • under "performance monitor", click add (+ sign) and monitor these two counters:

    • Cache/dirty pages: the amount of the write cache, in 4KB pages
    • Cache/Lazy write pages/sec: the speed at which the dirty pages are flushed to disk

Remember that a page is a 4KB element - in other words, if you see that 10.000 pages are dirty, this means 40 MB worth of data.

shodanshok
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