Page In/Out Rate

Good afternoon,

We often get Fatal: Abnormal page in and out rate warnings from Foglight everyday.  Current values are(same goes for Page In):

INF_MemoryPageOutRateLowestValue: 0.1
INF_MemoryPageOutRateFatal: 256.0
INF_MemoryPageOutRateFatalCount: 1

What do we check when we get these warnings?  Can these values be altered?  If yes, what is the ideal values?

Thank you!

  • Hi,

    This is an alarm that may have outlived it's usefulness. It's an indicator from the OS (eg. Windows) that it is reading from / writing to the page file vs. physical RAM. On physical hardware, this was important to know, as it could be indicative of a memory shortage. The page file was typically on a local spinning (slower) disk too.

    On a virtual machine, the page file is on the ESX host, typically SSD based. You can use the alarm to investigate memory issues - Windows is trying to tell you that it is writing to/reading from the page file. I would look quickly to see if the allocated memory of the VM is filling up, but you will also need to check from the VM side (vCenter, etc.) on how the virtual machine is using memory, what is allocated, etc. "Fixing" it could involve allocating more memory, increasing the share/priority to memory or even reserving it for the VM.