SAVECORE(8,C) AIX Commands Reference SAVECORE(8,C)
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savecore
PURPOSE
Manages core dumps of the operating system on the dump device.
SYNTAX
For AIX PS/2
+-----------+
/etc/savecore ------------ dirname ---| |---|
| +----+ | +- sysname -+
+-| -v |-+
^| -a ||
|+----+|
+------+
For AIX/370
+-------- -t ----------+ +- -d --- /dev/dump -+
/etc/savecore ---| +- -r --- dumpid --+ |---| |---|
+-| ^ ||-+ +- -d --- special ---+
| +--- , ----+|
| one of |
| +-----------+ |
+--| -e dumpid |---+
| -I -i |
| -t -l |
+-----------+
DESCRIPTION
The savecore command on both AIX/370 and AIX PS/2 is used to copy a core dump
of the operating system from the dump device into the AIX file system.
Note: You must have read/write access to the dump device.
SAVECORE ON AIX PS/2:
savecore checks the core dump to be certain it corresponds with the current
running unix. If it does it saves the core image in the file dirname/core.n
and the namelist, dirname/unix.n. The trailing .n in the path names is
replaced by a number which grows every time savecore is run in that directory.
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Savecore is often included near the end of the /etc/rc file so that a core
dump, if available, can be saved when the system reboots.
Before savecore writes out a core image, it reads a number from the file
dirname/minfree. If the number of free kilobytes on the file system which
contains dirname is less than the number obtained from the minfree file, the
core dump is not saved. If the minfree file does not exist, savecore always
writes out the core file (assuming that a core dump was taken).
savecore also logs a reboot message using facility LOG_AUTH. If the system
crashed as a result of a panic, savecore logs the panic string too.
If the core dump was from a system other than /unix, the name of that system
must be supplied as sysname.
SAVECORE ON AIX/370:
On AIX/370 it is possible for multiple core dumps to be stored concurrently on
the dump device, so on AIX/370 there are additional arguments with savecore to
allow one to manipulate these multiple dumps.
FLAGS
The following flags are for AIX/370 only:
-e dumpid Copies the dump specified by dumpid from the dump device, along
with its symbol table information, and send it to the standard
output.
-r dumpid,... Removes the dump(s) specified by dumpid(s) from the dump device
and reclaims all space. The dumpid will not be reused until the
dump device is reinitialized by the -I option.
-I or -i Clears all dumps from the dump device and initializes it for use
again.
-l Display the number of the latest dump having been produced in
the dump device. This is also the highest number being
allocated so far.
-t Prints a summary of all dumps in the dump device. The summary
contains
1. dumpid
2. size
3. AIX version
4. date
5. time
The listing is written to the standard output.
-d special Name of the dump device. The default is /dev/dump.
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SAVECORE(8,C) AIX Commands Reference SAVECORE(8,C)
The following flags are for PS/2s only:
-a Saves the dump if the date of the dump is greater than three
days from the current date.
-v Verbose option.
RESTRICTIONS
The following restrictions apply to AIX/370 only:
o Highest dumpid in the dump device can be 254. These dumpids are not reused
until /dev/dump is re-initialized.
o The AIX/370 /dev/dump as delivered can hold about four PANIC dumps.
o The usable size of the dump device is limited by the size of an in-core
map; therefore, it is equal to the smaller of
- the physical extents of the dump device
or
- the parameter NDUMPS.
EXAMPLE
The following example applies to AIX/370 only:
A typical sequence of savecore commands is
/etc/savecore -t
/etc/savecore -e 12 >dump12
/etc/savecore -r 12
crash -d dump12
This sequence will
1. list the dumpids and other data about dumps present in the dump device
2. copy dump 12 to an ordinary file
3. remove dump 12 from the dump device to allow its space to be reused
4. execute crash to interactively examine the dump.
FILES
/unix Current UNIX.
/dev/dump default dump device.
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SAVECORE(8,C) AIX Commands Reference SAVECORE(8,C)
RELATED INFORMATION
See the AIX Dump Facility in the AIX Managing Guide.
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