diff --git a/kexec-kdump-howto.txt b/kexec-kdump-howto.txt index 7ffeab9..5582e40 100644 --- a/kexec-kdump-howto.txt +++ b/kexec-kdump-howto.txt @@ -364,18 +364,46 @@ to send over the necessary ssh key file. Restart the kdump service via '/sbin/systemctl restart kdump.service' to commit this change to your kdump initrd. Path +==== +"path" represents the file system path in which vmcore will be saved. In +fact kdump creates a directory $hostip-$date with-in "path" and saves +vmcore there. So practically dump is saved in $path/$hostip-$date/. To +simplify discussion further, if we say dump will be saved in $path, it +is implied that kdump will create another directory inside path and +save vmcore there. + +If a dump target is specified in kdump.conf, then "path" is relative to the +specified dump target. For example, if dump target is "ext4 /dev/sda", then +dump will be saved in "$path" directory on /dev/sda. + +Same is the case for nfs dump. If user specified "nfs foo.com:/export/tmp/" +as dump target, then dump will effectively be saved in +"foo.com:/export/tmp/var/crash/" directory. + +Interpretation of path changes a bit if user has not specified a dump +target explicitly in kdump.conf. In this case, "path" represents the +absolute path from root. And dump target and adjusted path are arrived +at automatically depending on what's mounted in the current system. + +Following are few examples. + +path /var/crash/ +---------------- +Assuming there is no disk mounted on /var/ or on /var/crash, dump will +be saved on disk backing rootfs in directory /var/crash. + +path /var/crash/ (A separate disk mounted on /var) +-------------------------------------------------- +Say a disk /dev/sdb is mouted on /var. In this case dump target will +become /dev/sdb and path will become "/crash" and dump will be saved +on "sdb:/crash/" directory. + +path /var/crash/ (NFS mounted on /var) +------------------------------------- +Say foo.com:/export/tmp is mounted on /var. In this case dump target is +nfs server and path will be adjusted to "/crash" and dump will be saved to +foo.com:/export/tmp/crash/ directory. -By default, local file system vmcore files are written to /var/crash/%DATE -on the local system, ssh/scp dumps to /var/crash/%HOST-%DATE on the target -system, dedicated file system partition dumps to ./var/crash/%DATE, and -NFS dumps to ./var/crash/%HOST-%DATE, the latter two both relative to -their respective mount points within the kdump initrd (usually /mnt). The -'/var/crash' portion of the path can be overridden using kdump.conf's 'path' -variable, should you wish to write the vmcore out to a different location. For -example, 'path /data/coredumps' would lead to vmcore files being written to -/data/coredumps/%DATE if you were dumping to your local file system. Note -that the path option is ingnored if your kdump configuration results in the -core being saved from the initscripts in the root filesystem. Kdump Post-Capture Executable