Skip to main content

IIS : Virtual Memory

About Virtual Memory

Virtual Memory is not the same as memory stored on disk in the page file.
Virtual Memory is a concept of indirection introduced in memory addressing whereby application see a contiguous "virtual memory" address space, but the OS transparently fulfills that memory address space with EITHER physical memory (i.e. RAM) or something else like disk memory (i.e. pagefile).
From the application's perspective, it is simply using "memory". However, the OS knows whether that "memory" is real physical memory or has to be swapped in from the pagefile on disk into real memory. It is this swapping operation which makes virtual memory that is in the page file slow.
If you want more information on the subject, I suggest reading books like "Inside Windows 2000" or "Microsoft Windows Internals" by Solomon and Russinovich, or classic books like "Computer Architectures: A Quantitative Approach". I know that it's probably way more information and detail than you are asking for, but those are the authoritative sources that I go with...

Memory Fragmentation vs Memory Leak

The classic signs of Memory Fragmentation is if you have lots of physical RAM free, low committed memory, yet seeing Out Of Memory errors.
How to distinguish this from Memory leak? Well, Memory leak would consume your physical RAM such that very little is free, virtual memory would be maxed out, and you see Out Of Memory errors. When you see the error depends on when your Virtual Memory depletes - a pagefile simply delays the inevitable and eventually grinds the system to a halt.
Your issue looks like memory fragmentation.
Labels:

Comments

Post a Comment

Popular posts from this blog

SSL Certificate for IIS 8 in win 2012

                                                                       SSL How to create / import and configure self signed ssl certificate for IIS 8 in win 2012 Refer : http://www.youtube.com/watch?v=BYwOMuBDhPU http://www.entrust.net/knowledge-base/technote.cfm?tn=8713 1. Go to IIS 2. Select servername(TOP) 3. Middle area iis---->server certificate-->double click-->right side chosse & click created self certificate-->Specify a friendly name---> choose certificate type & click OK 4. Select site and right side BINDINGS--->Add-->Choose type https--->enter hostname and choose SSL cerificate---> ...
Post a Comment
Read more

How to add Microsoft Excel Application

Start Run mmc -32  or   DCOMCNFG -32 or dcomcnfg File Add Remove Snap-in Component Services Add OK Console Root Component Services Computers My Computer DCOM Config Microsoft Excel Application  Step to add:       Right click and select Properties->Select Identity Tab->Select This user and add the Administrator  accout and password  Select Security Tab, Under "Launch and Activation Permissions", Choose "Customize", Click "Edit" button, Add the everyone account and add all the Permissions        Do the same thing in "Access Permissions" and "Configuration Permissions".   Refer : http://journeytodotnetauthority.blogspot.in/2012/03/how-to-add-microsoft-excel-application.html
Post a Comment
Read more

IIS 7 Tip # 5 Run a command when Rapid Fail Protection is triggered

Rapid-Fail Protection disables application pools if they crash multiple times within in a specified time period. This prevents the failing application pool from getting into a continuous loop of crashing and restarting. This protects other application pools running on the server as repeated failures can consume lot of system resources. When rapid-fail protection kicks in it stops the application pool that is repeatedly crashing and your clients will start getting a 503 – Service Unavailable error. An administrator will have to manually enable the application pool again. You also have to option to configure an executable to run when ever rapid-fail protection is triggered. For example below I have configured the application pool to restart the IIS service using iisreset.exe … the /rebootonerror will reboot the whole server if iisreset.exe for some reason fails to restart the services. Refer http://blogs.msdn.com/b/vijaysk/archive/2009/03/13/iis-7-tip-5-run-a-command-when-rapid-f...
1 comment
Read more