Bug 857111
Summary: | The DUMPFILE field of vmcore showing "vmcore [PARTIAL DUMP]" | ||
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Product: | Red Hat Enterprise Linux 6 | Reporter: | Anil <dhaneshwar_anil> |
Component: | crash | Assignee: | Dave Anderson <anderson> |
Status: | CLOSED NOTABUG | QA Contact: | Red Hat Kernel QE team <kernel-qe> |
Severity: | medium | Docs Contact: | |
Priority: | unspecified | ||
Version: | 6.3 | CC: | xili |
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: | 2012-09-13 17:28:05 UTC | Type: | Bug |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Anil
2012-09-13 15:20:37 UTC
> 1.generate the vmcore by cmd "echo c > /proc/sysrq-trigger" > 2.read this vmcore using crash > 3.DUMPFILE field will show "DUMPFILE: vmcore [PARTIAL DUMP]" > > Is the meaning of [PARTIAL DUMP] means we havent got the full dump? > can I do my investigation on this dump? > > Also suggest if I miss any setting to take k-dump The system that crashed has been configured such that the vmcore is filtered by the makedumpfile facility to remove unnecessary pages. Check the crashed system's /etc/kdump.conf file. It probably has a line that configures "core_collector" to something like this: core_collector makedumpfile -c --message-level 1 -d 31 The -c means "compressed" and the "-d <number>" is a bitmask that allows you to filter out zero-filled pages, page-cache pages, user-program pages, and free-pages. This is the relevant section from "makedumpfile --help": [-d DL]: Specify the type of unnecessary page for analysis. Pages of the specified type are not copied to DUMPFILE. The page type marked in the following table is excluded. A user can specify multiple page types by setting the sum of each page type for Dump_Level (DL). The maximum of Dump_Level is 31. Note that Dump_Level for Xen dump filtering is 0 or 1. Dump | zero cache cache user free Level | page page private data page -------+--------------------------------------- 0 | 1 | X 2 | X 4 | X X 8 | X 16 | X 31 | X X X X X If your configuration also uses "-c" to make the vmcore file a compressed dumpfile, you can use the crash utility itself to access the dump-level value, like this example where -d31 was used: crash> help -n | grep dump_level dump_level: 31 (0x1f) (DUMP_EXCLUDE_ZERO|DUMP_EXCLUDE_CACHE|DUMP_EXCLUDE_CACHE_PRI|DUMP_EXCLUDE_USER_DATA|DUMP_EXCLUDE_FREE) crash> If "-c" was not used, then you would have to consult the /etc/kdump.conf file on the crashed machine to see how it was configured. In any case, it's highly unlikely that the contents of any of the filterable page-types above are necessary to investigate the cause of a kernel crash. |