freebsd-skq/cddl
avg c573dff5b0 zfsbootcfg: a simple tool to set next boot (one time) options for zfsboot
(gpt)zfsboot will read one-time boot directives from a special ZFS pool
area.  The area was previously described as "Boot Block Header", but
currently it is know as Pad2, marked as reserved and is zeroed out on
pool creation.  The new code interprets data in this area, if any, using
the same format as boot.config.  The area is immediately wiped out.
Failure to parse the directives results in a reboot right after the
cleanup.  Otherwise the boot sequence proceeds as usual.

zfsbootcfg writes zfsboot arguments specified on its command line to the
Pad2 area of a disk identified by vfs.zfs.boot.primary_pool and
vfs.zfs.boot.primary_vdev kenv variables that are set by loader during
boot.  Please see the manual page for more.

Thanks to all who reviewed, contributed and made suggestions!  There are
many potential improvements to the feature, please see the review for
details.

Reviewed by:	wblock (docs)
Discussed with:	jhb, tsoome
MFC after:	3 weeks
Relnotes:	yes
Differential Revision: https://reviews.freebsd.org/D7612
2016-10-29 14:09:32 +00:00
..
compat/opensolaris rename getline into zgetline to avoid collision with getline(3) 2016-05-10 07:50:57 +00:00
contrib/opensolaris zfsbootcfg: a simple tool to set next boot (one time) options for zfsboot 2016-10-29 14:09:32 +00:00
lib Unlike Solaris, in FreeBSD p_args can be 0 so check for that 2016-08-25 23:24:57 +00:00
sbin Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed 2016-05-04 23:20:53 +00:00
tests Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed 2016-05-04 23:20:53 +00:00
usr.bin Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed 2016-05-04 23:20:53 +00:00
usr.sbin tst.kpriv.ksh fails because DTrace privilege levels are unimplemented. 2016-10-16 19:46:55 +00:00
Makefile Add more SUBDIR_PARALLEL. 2015-10-15 22:55:08 +00:00
Makefile.inc Make DTrace stuff compile with C99 standard. 2014-08-22 20:04:51 +00:00