Comments on: Crash Dump Analysis Patterns (Part 62) https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/ Structural and Behavioral Patterns for Software Diagnostics, Forensics and Prognostics Wed, 06 May 2026 22:46:50 +0000 http://wordpress.org/?v=2.3.3 By: Crash Dump Analysis » Blog Archive » Insufficient memory, handle leak, wait chain, deadlock, inconsistent dump and overaged system: pattern cooperation https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-103490 Crash Dump Analysis » Blog Archive » Insufficient memory, handle leak, wait chain, deadlock, inconsistent dump and overaged system: pattern cooperation Sun, 08 Nov 2009 22:48:56 +0000 https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-103490 [...] We also notice the system uptime which might suggest that all these abnormalities had been gradually accumulated (see Overaged System): [...] […] We also notice the system uptime which might suggest that all these abnormalities had been gradually accumulated (see Overaged System): […]

]]> By: Crash Dump Analysis » Blog Archive » Crash Dump Analysis Patterns (Part 73) https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-36105 Crash Dump Analysis » Blog Archive » Crash Dump Analysis Patterns (Part 73) Tue, 29 Jul 2008 19:22:03 +0000 https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-36105 [...] to Overaged System sometimes we can see Young System pattern. This means that the system didn’t have time to [...] […] to Overaged System sometimes we can see Young System pattern. This means that the system didn’t have time to […]

]]> By: Chae https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-28851 Chae Thu, 29 May 2008 18:34:27 +0000 https://www.dumpanalysis.org/blog/index.php/2008/05/28/crash-dump-analysis-patterns-part-62/#comment-28851 Hello, Following is what happened one of our overaged servers. Virtual Memory Address fragmentation seems inevitable even if we're using LFH (Low Fragmentation Heap). This machine have had plenty of free physical memory but we had to restart the service. Usually large Uncommitted Ranges are bad but in this case 200 UCR caused 98% Virtual Address Fragmentation though which is a little bit strange. 0:020> !heap -s Heap Flags Reserv Commit Virt Free List UCR Virt Lock Fast (k) (k) (k) (k) length blocks cont. heap ----------------------------------------------------------------------------- 006c0000 00001002 2565820 7232 658924 1302 160 200 0 44f3b4 LFH External fragmentation 18 % (160 free blocks) Virtual address fragmentation 98 % (200 uncommited ranges) Hello,

Following is what happened one of our overaged servers. Virtual Memory Address fragmentation seems inevitable even if we’re using LFH (Low Fragmentation Heap). This machine have had plenty of free physical memory but we had to restart the service.

Usually large Uncommitted Ranges are bad but in this case 200 UCR caused 98% Virtual Address Fragmentation though which is a little bit strange.

0:020> !heap -s
Heap Flags Reserv Commit Virt Free List UCR Virt Lock Fast
(k) (k) (k) (k) length blocks cont. heap
—————————————————————————–
006c0000 00001002 2565820 7232 658924 1302 160 200 0 44f3b4 LFH
External fragmentation 18 % (160 free blocks)
Virtual address fragmentation 98 % (200 uncommited ranges)

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