dumpon(8) currently states: | The dumpon utility will refuse to enable a dump device which is smaller | than the total amount of physical memory as reported by the hw.physmem | sysctl(8) variable. If mini crash dumps are enabled smaller dump devices are actually accepted. It might also be worth mentioning that with mini crash dumps disabled no error message is printed unless -v is used. Fix: Update the man page. How-To-Repeat: fk@r500 ~ $sysctl debug.minidump debug.minidump: 1 fk@r500 ~ $sysctl kern.shutdown.dumpdevname kern.shutdown.dumpdevname: fk@r500 ~ $sysctl hw.physmem hw.physmem: 2070306816 fk@r500 ~ $diskinfo -v /dev/da0 | grep bytes 750780416 # mediasize in bytes (716M) fk@r500 ~ $sudo dumpon /dev/da0 fk@r500 ~ $echo $? 0 fk@r500 ~ $sysctl kern.shutdown.dumpdevname kern.shutdown.dumpdevname: da0 fk@r500 ~ $sudo dumpon off fk@r500 ~ $sudo sysctl debug.minidump=0 debug.minidump: 1 -> 0 fk@r500 ~ $sudo dumpon /dev/da0 fk@r500 ~ $echo $? 74 fk@r500 ~ $sudo dumpon -v /dev/da0 /dev/da0 is smaller than physical memory
Responsible Changed From-To: freebsd-doc->joel Take
State Changed From-To: open->closed I've updated the man page and I'm closing this PR. Thanks!
Author: joel (doc committer) Date: Tue Apr 30 07:22:03 2013 New Revision: 250095 URL: http://svnweb.freebsd.org/changeset/base/250095 Log: Adapt to the fact that minidumps are now on by default. PR: 177188 Modified: head/sbin/dumpon/dumpon.8 Modified: head/sbin/dumpon/dumpon.8 ============================================================================== --- head/sbin/dumpon/dumpon.8 Tue Apr 30 06:41:42 2013 (r250094) +++ head/sbin/dumpon/dumpon.8 Tue Apr 30 07:22:03 2013 (r250095) @@ -28,7 +28,7 @@ .\" From: @(#)swapon.8 8.1 (Berkeley) 6/5/93 .\" $FreeBSD$ .\" -.Dd May 12, 1995 +.Dd April 29, 2013 .Dt DUMPON 8 .Os .Sh NAME @@ -59,14 +59,21 @@ controlled by the variable in the boot time configuration file .Pa /etc/rc.conf . .Pp -For most systems the size of the specified dump device must be at +The default type of kernel crash dump is the mini crash dump. +Mini crash dumps hold only memory pages in use by the kernel. +Alternatively, full memory dumps can be enabled by setting the +.Va debug.minidump +.Xr sysctl 8 +variable to 0. +.Pp +For systems using full memory dumps, the size of the specified dump +device must be at least the size of physical memory. Even though an additional 64 kB header is added to the dump, the BIOS for a platform typically holds back some memory, so it is not usually necessary to size the dump device larger than the actual amount of RAM available in the machine. -.Pp -The +Also, when using full memory dumps, the .Nm utility will refuse to enable a dump device which is smaller than the total amount of physical memory as reported by the _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"
After updating the man page, I'll close this PR. https://flappy-bird.co