Tag Archives: Win08

How to measure Windows 2008 Memory usage

The counters you use to monitor Windows 2008 R2 RAM are the same with what you use to monitor Win 7.

  • If you want the best performance, use Total – Free as the sizing.
  • If you want a more cost effective solution, use Total – Free – Standby.
  • Keep % Committed to below 80%
  • Ensure pagefile.sys is not larger than the physical RAM. If Windows increase it, it’s a sign of it’s not having enough RAM.

To avoid repeat of blog, you can see the details recommendation here.

Windows 2008 R2 manages memory slightly differently to Windows 7 x64. While it is based on the same kernel, the difference is visible from what a small test that I conducted. I encourage you to perform your own real world test, not synthetic, in your environment.

Windows uses both the physical memory and virtual memory concurrently. The challenge is, if you look at the actual metrics, it is not clear how it actually prefers one over the other. In my case, Windows still had >300 MB of physical memory (on Standby and Free) yet Windows used the virtual memory extensively already. The paging file usage was >50% and it had increased the pagefile.sys size by 10%. Performance, at least from the UI, was however still good. This is different to Windows 7 x64, where the performance visibly dropped. Windows 7 in fact gave warning messages. Windows 2008 R2 just continued running well as if it had no memory shortage. The screenshot below showed the Standby actually dropped to 46 MB and Free dropped to a mere 8 MB in Windows 2008.

Windows 2008 running MS AD - 5 windows patch no warning whatsoever

Windows 7 64 bit, on the other hand, gave warning when it still had plenty of RAM. See the screenshot below. From the Task Manager, you can see that it only used 6.15 GB, meaning I still had 1.85 GB of physical RAM. From the Resource Monitor, I had 1709 MB Available RAM (Standby RAM + Free RAM). Plenty of physical RAM, as I disabled the paging file. Yet, Windows already gave a warning message, suggesting me to close an application. It suggested that I closed Windows Explorer.

0 Windows gave error message even though I have 1 GB free

I ignored it, since I had plenty of RAM. I opened a small application, which I knew would fit easily. I chose MS Paint. To my surprise, Windows 7 did not tolerate it. It opened MS Paint, but it gave an error. In fact, beyond giving warning, some applications actually crashed. In my case it was both MS Word and Google Chrome.

0 Hit issue - Word hit issue, Chrome hit issue

Another difference between Windows 7 x64 and Windows 2008 R2 is SuperFetch is disabled in the later. In fact, the service is hidden from the Services list. In Windows 7, it is not hidden. It is automatically disabled when Windows 7 detects it runs on SSD.

10 Windows7 superFetch disabled

Back to the Windows 2008. Since the memory is running low, it makes sense to increase. I changed it from 3 GB to 4 GB, and continued the update/patching process. Since I have more RAM, I also update Java at the same time. Notice the RAM is healthier now.

MS AD with 4 GB RAM - patch n Java

The next screenshot was after Java was installed, and it’s now doing Windows updates installation. While the Free Memory was low, the Standby Memory was acceptable. If you want to be conservative, you can increase it to 5 GB. For my use case, 4 GB is good enough.

MS AD with 4 GB RAM - patch - better 2

I hope you find the information useful. Follow this to see how to use vRealize Operations End Point to monitor Windows memory.