Is the system still usable?
If the system reboots itself after a panic,
Assuming that the system is usable for now, you can use the system to analyze the savecore files that are awaiting you in the savecore directory.
If your system is one that serves several users, whether directly or indirectly as a data server, you may want to notify your
If you have not
Turn off savecore? (How many dumps will you need?)
Once an image of a system crash has been captured, you need to again assess how you are doing on disk space. Do you have room for a
At this time, the second question you need to ask yourself is whether you really need another set of postmortem files? To answer this, you need to consider the recent history of the system's performance. Has it been crashing a lot lately and you've just enabled savecore to capture one crash? Have the symptoms of the past crashes been reliably predictable?
For example, if your system crashes only when you boot a certain kernel, you probably only need the one set of savecore files and can disable savecore for the time being. If, however, your system has never crashed before, it would be wise to keep savecore enabled for now. It is often a good idea to have at least two or more sets of crashes for comparison.
Generally speaking, we feel savecore should always be enabled and ready to go in case the worst happens and your system decides to panic.
If you choose to maintain the
files on disk, use the UNIX
command to squeeze them down to a smaller
Figure 4-1 Compress your savecore files to save disk space
Hiya... ls -l total 268154 -rw-rw-rw- 1 kbrown 15 1272308 Sep 1 12:28 unix.0 -rw-rw-rw- 1 kbrown 15 135077888 Sep 1 12:29 vmcore.0 Hiya... compress unix.0 vmcore.0 Hiya... ls -l total 51082 -rw-rw-rw- 1 kbrown 15 669336 Sep 1 12:28 unix.0.Z -rw-rw-rw- 1 kbrown 15 24592643 Sep 1 12:29 vmcore.0.Z Hiya...
The 135-megabyte vmcore.0 file compressed to less than 25 megabytes ” a huge saving!
Saving the crash to tape for shipment or archives
When archiving a set of crash dumps to tape, you may wish to first compress the ( vm ) unix. X and vmcore. X files, again, to use less media space. This also makes life a bit easier for the person who will later read the tape onto his own system to analyze the files, initially allowing him to use less disk space until he is ready to uncompress the files and start the analysis work.
When compressing the files,
After writing the files to tape,
write-protect the tape
and, only then, verify that you can read the tape successfully. Too many
Finally, label the tape!
files are safely archived, you can remove them from the disk. In general, it is a good idea to maintain the
file, which contains the
If you plan to send the tape to another person for analysis, it is best to provide the following information:
The more information you can provide to the person who will analyze the crash files, the better idea he will have of where to start his search for the cause of the problem.
Solaris Performance and Tools: DTrace and MDB Techniques for Solaris 10 and OpenSolaris
DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD (Oracle Solaris Series)
Practical Guide to Fedora and Red Hat Enterprise Linux, A (6th Edition)
An Introduction to GCC: For the GNU Compilers GCC and G++