date and time created 86/03/02 15:30:40 by sam

[unix-history] / usr / src / old / analyze / analyze.8

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)analyze.8	6.1 (Berkeley) %G%
.\"
.TH ANALYZE 8 ""
.UC 4
.lg 0
.SH NAME
analyze \- Virtual UNIX postmortem crash analyzer
.SH SYNOPSIS
.B /etc/analyze
[
.B \-s
swapfile
] [
.B \-f
] [
.B \-m
] [
.B \-d
] [
.B \-D
] [
.B \-v
]
corefile
[ system ]
.SH DESCRIPTION
.I Analyze
is the post-mortem analyzer for the state of the paging system.
In order to use
.I analyze
you must arrange to get a image of the memory (and possibly the
paging area) of the system after it crashes (see
.IR crash (8V)).
.PP
The
.I analyze
program reads the relevant system data structures from the core
image file and indexing information from 
.B /vmunix
(or the specified file)
to determine the state of the paging subsystem at the point of crash.
It looks at each process in the system, and the resources each is
using in an attempt to determine inconsistencies in the paging system
state.  Normally, the output consists of a sequence of lines showing
each active process, its state (whether swapped in or not), its
.IR p0br ,
and the number and location of its page table pages.
Any pages which are locked while raw i/o is in progress, or which
are locked because they are
.I intransit
are also printed.  (Intransit text pages often diagnose as duplicated;
you will have to weed these out by hand.)
.PP
The program checks that any pages in core which are marked as not
modified are, in fact, identical to the swap space copies.
It also checks for non-overlap of the swap space, and that the core
map entries correspond to the page tables.
The state of the free list is also checked.
.PP
Options to
.IR analyze :
.TP
.B \-D
causes the diskmap for each process to be printed.
.TP
.B \-d
causes the (sorted) paging area usage to be printed.
.TP
.B \-f
which causes the free list to be dumped.
.TP
.B \-m
causes the entire coremap state to be dumped.
.TP
.B \-v
(long unused) which causes a hugely verbose output format to be used.
.PP
In general, the output from this program can be confused by processes
which were forking, swapping, or exiting or
happened to be in unusual states when the
crash occurred.  You should examine the flags fields of relevant processes
in the output of a
.IR pstat (8)
to weed out such processes.
.PP
It is possible to look at the core dump with
.I adb
if you do
.IP
adb \-k /vmunix /vmcore
.SH FILES
/vmunix	default system namelist
.SH SEE ALSO
adb(1), ps(1), crash(8V), pstat(8)
.SH AUTHORS
Ozalp Babaoglu and William Joy
.SH DIAGNOSTICS
Various diagnostics about overlaps in swap mappings, missing swap mappings,
page table entries inconsistent with the core map, incore pages which
are marked clean but differ from disk-image copies, pages which are
locked or intransit, and inconsistencies in the free list.
.PP
It would be nice if this program analyzed the system in general, rather
than just the paging system in particular.