From: root@candle.uucp (Bruce Momjian)
Subject: Re: Description for the CRASH-Utility
Organization: a consultant's basement
Date: Mon, 11 Jan 1993 22:32:25 GMT
X-Newsreader: TIN [version 1.1 PL6]

3730 (robert@kommu.UUCP) wrote:
: I was wondering if somebody has a description of the 
: "crash" - Utility. I am asking for a more detailed 
: description.

Here is a diagram I worked on.  Capitalized words represent crash commands.
----
PROCess               Virual        Segment/Page        Physical
 table                Memory         Descriptor          Memory      
 ______               ______           Tables            ______
|______|             |_text_| \               PDT       |______|\
|______| ------>     |______|  \    SDT       ___   /-->|______| \
|______|             |_data_|   \   ____   ->|___|--    |______|  \     
|______|             |______|    \ |____| /  |___|----->|______|
|______|             |______|     \|____|-   |___|-_    |______|    PFDATa
|______|             |      | -->  |____|           \   |______|    ___ 
|______|             |STACK_|     /|____|---         \->|______|   |___|
|______|             |------|    / |____|   |           |______| <-|___|->swap
                     |kernel|   /           | PDT    /->|______|   |___|
                     |------|  /            | ___   /   |______|   |___|
                 ----|_USER_| /             >|___|-- /->|______|
                |    |______|/               |___|---   |______|    
                |                            |___|----->|______|  /
                |                                       |kernel| /
                |                                       |______|/
                | 
     ----------- 
    |
    V 

USER File        
Descriptor       FILE          INODE                          
  Table          Table         Table                            Disk
 ______         ______         ______                          ______
|______|------>|______|---_   |______|                        |_boot_|
|______|       |______|    \->|______|--------------------_   |super_|
|______|---_   |______|       |______|                     \->|inode_|
|______|    \->|______|-------|______|----------------------->|inode_|
|______|---_   |______|    /->|______|--------------------_   |inode_|
|______|    \->|______|----   |______|                     \->|inode_|
|______|       |______|--_    |______|                     _->|inode_|
               |______|   \   |______|                    /  -|_free_|
               |______|    \->|______|--------------------  | |inode_|
               |______|       |______|                      | |inode_|
               |______|       |______|                      | |_free_|
               |______|       |______|                      | |_data_|
                                                            | |_data_|
                                                            | |_free_|
                                          Buffer            | |_data_|
                                          Headers           | |_free_|
                                          BUFHDR    BUFFERs | |_free_|
                                          ______       __   | |_data_|
                                         |______|---->|  |<-  |_free_|
                                         |______|      --     |_data_|
                                         |______|      __    _|_data_|
                                         |______|---->|  |<-/ |_free_|
                                         |______|      --     |_free_|
                                         |______|      __     |_data_|
                                         |______|---->|  |<---|_data_|
                                         |______|      --     |_free_|
                                                              |_swap_|
                                                              |_swap_|
                                                              |_swap_|
                                                 

-- 
Bruce Momjian                          |  830 Blythe Avenue
root%candle.uucp@bts.com               |  Drexel Hill, Pennsylvania 19026 
  +  If your life is a hard drive,     |  (215) 353-9879(w) 
  +  Christ can be your backup.        |  (215) 853-3000(h)
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