Re: Bug in 7.2.2 for Digital UNIX possibly others
We were having 4GL compile time errors (assert fail) with a DEC Alpha
running:
O/S: Digital UNIX V4.0A
OnLine DS: V7.22.FC2
I4GL RDS: V6.04.UC1
NETTYPE: onsoctcp (which seems to be getting changed in the onconfig
file to "soctcp,,,")
The compiles would fail and the system message log file would have errors like:
16:10:57 Assert Failed: Page Check Error in rsread:bad data page
16:10:57 Who: Session(74, dbadmin@tracdec27, 10065, 9439224)
Thread(1778, sqlexec, 2008cd988, 1)
16:10:57 Results: Possible inconsistencies in 'tracsy:"informix".systables'
16:10:57 Action: Run 'oncheck -cD 1048992'
16:10:57 See Also: /tmp/af.6f21b4f
Then we got the following email about the O/S alerting us to a possible
problem; once we implemented the workaround, the compile time errors stopped
completely.
} You may have already been notified by Digital about this potential
} problem in Digital UNIX V4.0 and later versions of the OS. Digital UNIX
} Engineering is investigating the exact cause of the problem; however,
} until we fully understand the circumstances surrounding this, you should
} follow the recommended workaround detailed below.
}
} All I know right now, is that under very heavy loads (with OPS and DRD)
} this data corruption problem can occur. Even if you are not running
} Oracle Parallel Server, we recommend you implement the workaround
} because we don't fully know the cause of the problem. Systems running
} Digital UNIX V3.2x are not affected by this problem.
}
} BLITZ TITLE: DIGITAL UNIX DATA CORRUPTION WITH SHARED MEMORY
}
}
} DATE: 16 April 1997
[snip]
} During the course of prereleased hardware testing with Digital UNIX
} Versions 4.0 and later, the Digital UNIX Engineering Group discovered
} a user application data corruption that was not detected by the
} operating system software.
}
} PROBLEM:
}
} A data corruption problem can occur when the parameter new-wire-method
} is turned on. The new-wire-method parameter is only available in V4.0
} and later releases. All versions V4.0 and later ship with the default
} being new-wire-method enabled.
}
} RESOLUTION/WORKAROUND:
}
} The workaround for this problem is as follows:
}
} The problem can be eliminated by turning off the new-wire-method.
}
} 1) Become the root user.
}
} 2) Create a new file named /tmp/nwm and insert the following lines:
}
} vm:
} new-wire-method=0
}
} 3) Execute the sysconfigdb command as follows:
}
} # /sbin/sysconfigdb -f /tmp/nwm -m vm
}
} 4) Reboot the system.
}
} The new-wire-method option is now disabled.
}
} Please note that turning off the new-wire-method should cause
} little or no performance degradation.
}
} It is the Strong Recommendation of Digital UNIX Engineering that
} this workaround be implemented on all systems running Digital UNIX
} V4.0 and above. Failure to do so can result in undetected data
} corruption.
}
} ADDITIONAL COMMENTS:
}
} Digital UNIX Engineering is working at the highest priority on a
} solution that will not require the above workaround. When the
} resultant fix is ready, an advisory blitz will announce its
} availability.
--
_____________________________________________________________________
| Colin McGrath cmm@trac3000.ueci.com |
| Raytheon Engineers & Constructors, Inc. (215) 422-4144 |
| Phila, PA, USA Standard Disclaimers Apply |
|___________________________________________________________________|