[ Bottom of Page | Previous Page | Next Page | Contents | Index | Library Home | Legal | Search ]

Commands Reference, Volume 2

dumpcheck Command


Checks to see that the dump device and copy directory are able to receive the system dump. An error is logged by default if there will likely be insufficient resources to accommodate the dump.


/usr/lib/ras/dumpcheck [ [ -l ] [ -p ] [ -t TimeParameters ] [ -P ] ] | [ -r ]


The /usr/lib/ras/dumpcheck command is used to check the disk resources used by the system dump. The command logs an error if either the largest dump device is too small to receive the dump or there is insufficient space in the copy directory when the dump is to paging space.

dumpcheck is normally run by cron at 3:00 pm local time each day. This can be varied using the -r flag to remove it from root's crontab or -t TimeParameters to change the time at which dumpcheck is executed. It may also be configured from SMIT. dumpcheck is automatically added to root's crontab when the service aids are installed.

For maximum effectiveness, dumpcheck should be run when the system is most heavily loaded. At such times, the system dump is most likely to be at its maximum size. Also, even with dumpcheck watching the dump size, it may still happen that the dump would not fit on the dump device or in the copy directory at the time it happens. This could occur if there is a peak in system load right at dump time.

The dumpcheck function is installed as part of the service aids file set, installed automatically.


-l Logs any warnings to the error log. This is the default if no parameters are specified.
-p Prints any warnings produced to stdout.
-P Indicates that the changes are to be made permanently; that is, they apply to subsequent executions of the dumpcheck facility. The -P flag is unnecessary with the -t and -r flags. If the -P flag is specified, dumpcheck simply changes the crontab entry without performing any checks.
-r Removes the crontab entry for this function, effectively unconfiguring it. This command is normally run by cron. The -r flag must be specified alone. It is not valid with any other flags.
-t TimeParameters Changes the time when dumpcheck is executed. The TimeParameters flag must be enclosed within single or double quotes. It specifies the crontab time parameters, the first five parameters of a line in the crontab file. See the crontab command for the format of the time parameters. The -t flag is invalid with the -r flag. If the -t flag is specified, dumpcheck just changes the crontab entry without performing any checks.


This command can only be executed by the root user.


  1. To check dump resources and have the results printed to standard output rather than logged, type:

    /usr/lib/ras/dumpcheck -p

    To make this change permanently; that is, to have it made in the crontab entry, type:

    /usr/lib/ras/dumpcheck -p -P
  2. To have dumpcheck run at 9:00 am and 3:00 pm Monday through Friday, type:

    /usr/lib/ras/dumpcheck -t "0 9,15 * * 1-5"

    To return to the default, type:

    /usr/lib/ras/dumpcheck -t "0 15 * * *"

    You may also use SMIT to configure the times when dumpcheck executes.

  3. To discontinue running this feature, type:

    /usr/lib/ras/dumpcheck -r

    You may also use SMIT for this task.

Related Information

The sysdumpdev command.

System Dump Facility in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.

[ Top of Page | Previous Page | Next Page | Contents | Index | Library Home | Legal | Search ]