Bug 663143
| Summary: | All VMs lost network connectivity | ||||||||||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | Simon Gao <gao> | ||||||||
| Component: | xen | Assignee: | Laszlo Ersek <lersek> | ||||||||
| Status: | CLOSED DUPLICATE | QA Contact: | Virtualization Bugs <virt-bugs> | ||||||||
| Severity: | high | Docs Contact: | |||||||||
| Priority: | low | ||||||||||
| Version: | 5.5 | CC: | drjones, lersek, xen-maint | ||||||||
| Target Milestone: | rc | ||||||||||
| Target Release: | --- | ||||||||||
| Hardware: | x86_64 | ||||||||||
| OS: | Linux | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2010-12-15 20:07:41 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: | |||||||||||
| Attachments: |
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Description
Simon Gao
2010-12-14 19:56:07 UTC
This is likely a dup of bug 653262. (In reply to comment #1) > This is likely a dup of bug 653262. Simon, can you please post the host's "/proc/xen/balloon" and xend's DEBUG log? Thanks. Created attachment 468916 [details]
Xen log
# cat /proc/xen/balloon Current allocation: 14086144 kB Requested target: 14086144 kB Low-mem balloon: 18405040 kB High-mem balloon: 0 kB Driver pages: 1024 kB Xen hard limit: ??? kB Created attachment 468939 [details] egrep 'Balloon: [0-9]{1,5} KiB free' From the /proc/xen/balloon contents in comment 4 it seems that there is plenty of free memory; Current allocation == Requested target. However this may not be the case when all those guests are starting up. There are several lines in the xend log that suggest a low-running balloon, see the attachment. It would be interesting to correlate (by timestamp) these xend.log entries with the netback memory pressure lines in the syslog. Is auto-ballooning turned on? # grep -B3 auto-balloon /etc/xen/xend-config.sxp # Automatically balloon dom0 down if try to balloon domU up for more memory # that is free. (auto-balloon-dom0 no) Whatever causes the memory pressure, ballooning or not, the fixes for bug 653262 and bug 653501 take page reassignment between guest and host (flipping) out of the netfront-netback communication. Is it possible to repeat the many guests test with those? Created attachment 468941 [details]
Syslog containing memory squeeze messages
If auto-ballooning is turned on by default, then yes. # grep -i balloon /etc/xen/xend-config.sxp # Dom0 will balloon out when needed to free memory for domU. # If dom0-min-mem=0, dom0 will never balloon out. For example these are very close to each other: [2010-12-14 10:33:22 xend 6413] DEBUG (balloon:151) Balloon: 1032 KiB free; 0 to scrub; need 4096; retries: 20. [2010-12-14 10:33:22 xend 6413] DEBUG (balloon:145) Balloon: 4104 KiB free; need 4096; done. [2010-12-14 10:33:22 xend 6413] DEBUG (balloon:151) Balloon: 4096 KiB free; 0 to scrub; need 2097152; retries: 25. and messages:Dec 14 10:33:31 xenserver kernel: xen_net: Memory squeeze in netback driver. messages:Dec 14 10:33:36 xenserver kernel: xen_net: Memory squeeze in netback driver. messages:Dec 14 10:33:43 xenserver kernel: xen_net: Memory squeeze in netback driver. messages:Dec 14 10:33:46 xenserver kernel: xen_net: Memory squeeze in netback driver. The fixes for bug 653262 and bug 653501 make the memory squeeze path in netback unreachable, so I'm closing this as a duplicate for now. *** This bug has been marked as a duplicate of bug 653262 *** |