Bug 193696
| Summary: | Not using all available system memory - swapping too aggressive - high load average (iowait) | ||||||
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| Product: | Red Hat Enterprise Linux 4 | Reporter: | David Herselman <bbs2web> | ||||
| Component: | kernel | Assignee: | Kernel Maintainer List <kernel-maint> | ||||
| Status: | CLOSED DUPLICATE | QA Contact: | Brian Brock <bbrock> | ||||
| Severity: | high | Docs Contact: | |||||
| Priority: | medium | ||||||
| Version: | 4.0 | ||||||
| Target Milestone: | --- | ||||||
| Target Release: | --- | ||||||
| Hardware: | i686 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2006-06-01 17:36:40 UTC | Type: | --- | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 181409 | ||||||
| Attachments: |
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Created attachment 130298 [details]
MRTG graph of available system memory show system not using everything before starting to aggressively swap
hmmm...this looks a lot like bz #188141. Can you please try the U4 beat kernel and let me know if this fixes it for you. The kernel is 2.6.9-37. http://people.redhat.com/~jbaron/rhel4/ Found additional information from other people experiencing the same issue in CentOS 4: Bug ID: 0001174 Summary: Extremely high load average and 100% CPU utilization URL: http://bugs.centos.org/view.php?id=1174 Yes, i'm aware of this. I'm pretty sure the U4 beta kernel mention =ed in comment #2 will resolve this issue. Also, just to be clear no VM tuning should be needed. The kernel-2.6.9-37.EL perfectly resolves the problem we were experiencing. Many thanks for your prompt assistance! |
Description of problem: System swaps too aggressively and only utilises +-30% of available system memory (reading discussion threads indicates that this only shows up when the system has more than 1GB of RAM). Version-Release number of selected component (if applicable): RHEL4.3 kernel-2.6.9-34.0.1.EL How reproducible: Very Steps to Reproduce: 1. AMD Athlon 64 3000+ Processor 2. nVidia nForce4 chipset (ASUS A8N5X Motherboard) 3. 1GB of RAM Actual results: put load on the server and available system memory is +-750KB. Swap utilisation increases and processes increase slowing the system due to high iowait (aggressive memory swapping) Expected results: Should only start swapping once system memory starts getting low, no? Additional info: System was previously running RHEL3.7 without problems, MRTG display of available system memory shows the problem quite clearly (attached). RedHat do have a document called 'Understanding Virtual Memory In Red Hat Enterprise Linux 4' but I simply don't understand what I should be changing: http://people.redhat.com/nhorman/papers/rhel4_vm.pdf