Installer changes on master (does not effect release)

Matthew Dillon dillon at
Mon Dec 14 11:53:40 PST 2015

    Master has gotten an installer revamp w/regards to the partition

    Previously the installer used radically different arrangements for UFS
    vs HAMMER.  UFS put an integrated boot+root on partition 'a', swap on 'b',
    and HAMMER put boot on 'a', swap on 'b', and root on 'd'.  HAMMER installs
    also created a whole bunch of PFS's for various major directories such
    as /home.

    The new setup is more uniform.  An 'a' boot, 'b' swap, 'd' root, and
    'e' /build is created whether UFS or HAMMER is chosen.  PFS's are no
    longer used.  Instead, major directories which generally do not have
    to be backed up (such as /usr/obj) are put on /build and null-mounted
    to their appropriate places via the fstab.  Major directories which
    typically do need to be backed up, such as (most of /var), /home, /usr,
    and /usr/local remain on the root filesystem.

    The new setup handles small drives (typically < 40GB) by not creating
    a separate /build partition.  It still creates the /build directory
    infrastructure on the root filesystem and still creates the null-mounts,
    making it relatively easy for the user to manage later on if/when moving
    to a setup with more storage.


    I've been using this scheme very successfully at home and on servers
    for more than a year now and really like the flexibility and ease of
    management.  The null mounts are a lot easier for users to manage than
    the hammer PFS's, and the separation reduces the chances of the root
    filesystem becoming corrupt during a crash.

    These changes also allow UFS installs to use encrypted roots which they
    could not before.  While we recommend HAMMER over UFS generally, there
    are still a few cases where UFS is more convenient, such as on small
    storage media / USB flash drives.

					Matthew Dillon 
					<dillon at>

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