Tips and tricks. Is it safe to run sysreport in production?

Sysreport is a diagnostic utility. It collects information about the running system, which is used for Red Hat Support to analyze current problems with the system. While sysreport is generally considered non-invasive, diagnostic utilities should always be run with caution.

In Red Hat Enterprise Linux 3 Update 7, and Red Hat Enterprise Linux 5.0, a change was introduced to sysreport. In the new version, sysreport will issue a “sysrq t” to the kernel by default. This collects a backtrace on every running process. As such, it can cause unexpected problems such as application freezes, scsi reset errors, and bonding failovers. Sysrq is especially invasive and should never be collected in production. It should only be run when specific debugging information is needed to troubleshoot certain types of problems during scheduled outage windows.

While sysreport should always be run with caution, Red Hat is correcting this default behavior in sysreport on Red Hat Enterprise Linux 3 and 5.0. An errata release will make sysrq non-default with sysreport. For version 5.0, the errata has already been released and is available on RHN. For version 3, an older version of sysreport (from Update 6 or earlier) can be used in the place of the current version. More details can be found in the following Bugzilla links:

# Version 3: https://bugzilla.redhat.com/show_bug.cgi?id=348981
# Version 5: https://rhn.redhat.com/rhn/errata/details/Details.do?eid=5836

Sysreport in Red Hat Enterprise Linux 4 and 5.1 do not run Syrq by default, but as with all diagnostic utilities, caution should be employed appropriately.

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This entry was posted by the editorial team on Monday, December 10th, 2007 at 9:00 am and is filed under tips and tricks. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.