Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (4.2BSD)
Apropos / Subsearch:
optional field

ANALYZE(8)                  System Manager's Manual                 ANALYZE(8)

       analyze - Virtual UNIX postmortem crash analyzer

       /etc/analyze  [  -s swapfile ] [ -f ] [ -m ] [ -d ] [ -D ] [ -v ] core-
       file [ system ]

       Analyze is the post-mortem analyzer for the state of the paging system.
       In  order  to use analyze you must arrange to get a image of the memory
       (and possibly the paging area) of the  system  after  it  crashes  (see

       The  analyze program reads the relevant system data structures from the
       core image file and indexing information from /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 sys-
       tem state.  Normally, the output consists of a sequence of lines  show-
       ing  each  active  process,  its state (whether swapped in or not), its
       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 intransit are also  printed.   (Intransit  text  pages
       often diagnose as duplicated; you will have to weed these out by hand.)

       The program checks that any pages in core which are marked as not modi-
       fied 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 corre-
       spond to the page tables.  The state of the free list is also checked.

       Options to analyze:

       -D     causes the diskmap for each process to be printed.

       -d     causes the (sorted) paging area usage to be printed.

       -f     which causes the free list to be dumped.

       -m     causes the entire coremap state to be dumped.

       -v     (long unused) which causes a hugely verbose output format to  be

       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 pstat(8) to weed  out  such  pro-

       It is possible to look at the core dump with adb if you do

              adb -k /vmunix /vmcore

       /vmunix   default system namelist

       adb(1), ps(1), crash(8V), pstat(8)

       Ozalp Babaoglu and William Joy

       Various  diagnostics about overlaps in swap mappings, missing swap map-
       pings, 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.

       It would be nice if this program analyzed the system in general, rather
       than just the paging system in particular.

4th Berkeley Distribution       4 February 1983                     ANALYZE(8)