Hi. On Tue, Feb 12, 2013 at 06:15:51PM +0100, John Marino wrote: > The following has happened to me a few times in the last 2 years: > > 1) I create a modification to world source > 2) "make buildworld" completes successfully > 3) Halfway through "make installworld" the system coredumps > everywhere due to bug introduced in step 1). > > With the kernel, you can always just launch the previous kernel > which was backed up prior to the new kernel getting installed.
You can set up a chroot jail to examine the experimental world before overwriting your installation: # hammer mirror-copy / /pfs/testworld (this works for me as the root filesystem is kept small on my system; you may want to use cpdup, rsync or some other tools, YMMV) # mount -tnull /pfs/testworld /mnt # cpdup /var /mnt/var # cpdup /boot /mnt/boot (repeat this for other filesystems which are parts of the base system) # mount -tnull -o ro /usr/src /mnt/usr/src # source tree should work RO # mount -tnull -o ro /usr/obj /mnt/usr/obj # obj tree can be RO, too # mount -tdevfs devfs /mnt/dev # mount -ttmpfs tmpfs /mnt/tmp # chroot /mnt # cd /usr/src && make installworld && MAKEOBJDIRPREFIX=/tmp make upgrade vkernel is a safer alternative as it doesn't share /dev, but it'll take much longer to complete the procedure depending on the storage performance.
