SAVECORE(8) 386BSD System Manager's Manual SAVECORE(8)
NAME
savecore - save the details of a crash of the operating system
SYNOPSIS
savecore dirname [system]
DESCRIPTION
Savecore is meant to be called near the end of the initialization file
/etc/rc (see rc(8)). Its function is to detect the presence and save the
state of the operating system's previous abnormal termination, assuming
the state was recorded for this purpose. If this state information is
found, savecore will also write a reboot message in the shutdown log.
The state information is a snapshot of all RAM memory at the time of
abnormal termination, untranslated by the processor's memory management
unit, in physical rather than virtual order (like the memory device, see
mem(4)).
Operands supported by savecore:
dirname The directory name where the core dump will be written.
system If the core dump was from a system other than /386bsd, the
name of that system must be supplied as system.
Savecore looks for a physical RAM memory image of the current system
(currently recorded during system crashes in the system's swap space) and
it checks the image for veracity. If the saved memory image is valid, it
saves this in dirname/ram.n and the current version of the operating
system's executable file in dirname/system.n Sequence numbers are
incremented and appended to the end of the pathnames each time savecore
is run in the directory.
Before savecore writes out a memory image, it reads a number from the
file dirname/minfree. If the number of free kilobytes on the filesystem
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 (see
syslog(3)) If the system crashed as a result of a panic, savecore logs
the panic string too.
FILES
/386bsd current system executable file
BUGS
Can be fooled into thinking a core dump is the wrong size.
HISTORY
The savecore command appeared in 4.1BSD.
4th Berkeley Distribution March 16, 1991 1