An improved dump mechanism is provided that increases the percentage of valid kernel dumps. Double-panic processing has been improved and the frequency of hangs during system dumps has been reduced. The dump I/O size has been increased from 8K to 64K. The overall speed of the dump process has also been improved.
Following a system panic and before reboot begins, the stack backtrace and register values are now written to the /var/adm/syslog file. This acts as a ``fingerprint'' of what happened, in case the dump save was not successful.
In addition, a system dump can now be obtained on demand, on a live system, with the new dumpmemory(1M) command. A dump thus obtained can be analyzed with crash(1M) just as any other dump.