Re:FreeBSD 11.1 released
by JdeBP on Thursday July 27, 2017 @02:58AM
(#14863202)
Ubuntu does not make the use of ZFS that one sees in the FreeBSD world. An example is TrueOS.
On TrueOS out of the box everything is ZFS, even the root volume, and that has been the case for a while, now. The operating system is in a single ZFS dataset (with things like /usr/ports, /usr/jails, /var/mail, /var/log, /usr/obj, and /usr/home split off into their own datasets). This is used to provide "boot environments".
System upgrade goes like this: The upgrade script makes a clone of the current operating system dataset, mounts it, and runs freebsd-upgrade on it chrooted at the mount point. This results in a new boot environment with the upgraded operating system ready to be rebooted into. ZFS copy-on-write means that an upgrade does not consume twice the disc space; and the separate dataset means that one retains an untouched current boot environment throughout the process.
On TrueOS out of the box everything is ZFS, even the root volume, and that has been the case for a while, now. The operating system is in a single ZFS dataset (with things like /usr/ports, /usr/jails, /var/mail, /var/log, /usr/obj, and /usr/home split off into their own datasets). This is used to provide "boot environments".
System upgrade goes like this: The upgrade script makes a clone of the current operating system dataset, mounts it, and runs freebsd-upgrade on it chrooted at the mount point. This results in a new boot environment with the upgraded operating system ready to be rebooted into. ZFS copy-on-write means that an upgrade does not consume twice the disc space; and the separate dataset means that one retains an untouched current boot environment throughout the process.
* https://github.com/trueos/pc-updatemanager