On Jul 22, 2013, at 12:29 AM, Andriy Gapon wrote: > > [turning this into a public discussion with Glen's permission] > > on 10/07/2013 21:05 Glen Barber said the following: >> Hi, >> >> My setup is like this: >> >> root_at_nucleus:/usr/src # zpool list >> NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT >> zboot0 9.94G 379M 9.57G 3% 1.00x ONLINE - >> zroot0 159G 113G 46.2G 70% 1.00x ONLINE - >> >> root_at_nucleus:/usr/src # zpool get bootfs >> NAME PROPERTY VALUE SOURCE >> zboot0 bootfs - default >> zroot0 bootfs - default >> >> root_at_nucleus:/usr/src # zfs list zboot0 >> NAME USED AVAIL REFER MOUNTPOINT >> zboot0 379M 9.41G 281M /bootdir >> >> root_at_nucleus:/usr/src # zfs list zroot0 >> NAME USED AVAIL REFER MOUNTPOINT >> zroot0 113G 43.7G 147M / >> >> 'zroot0' is a GELI-backed pool, so I have this to fix the boot process: >> >> root_at_nucleus:/usr/src # ll /boot >> lrwxr-xr-x 1 root wheel 12 Aug 25 2012 /boot_at_ -> bootdir/boot >> >> I upgraded from head/ on July 1 to r253159, and when I rebooted the >> system, I could correctly boot from the "/bootdir/boot". Once I enter >> the GELI passphrase, "/" (from zroot0) is mounted. Normally, everything >> would be okay at that point, but since the upgrade, "/bootdir/boot" >> disappears because the zboot0 pool is not imported as it was before. >> >> Any thoughts? > > I think that this setup (on ZFS level) is quite untypical, although not > impossible on FreeBSD (and perhaps only FreeBSD). > It's untypical because you have separate boot pool (where loader, loader.conf > and kernel are taken from) and root pool (where "/" is mounted from). > > There is this "magic" zpool.cache file that essentially tells what pools should > be automatically imported. On FreeBSD this file lives in /boot/zfs directory > while originally (in Solaris and its descendants) its home is /etc/zfs. > > Until recently FreeBSD could use only zpool.cache from a boot pool and, in fact, > if a root pool was different from a boot pool the root pool had to be in > zpool.cache. > I changed things a little bit and now a root pool does not have to be in > zpool.cache. Also, now zpool.cache is taken from the root > pool, or to be more precise from a root filesystem (whatever happens to be > /boot/zfs/zpool.cache after "/" is mounted). I am considering if perhaps now we > should move zpool.cache back to /etc/zfs/. > > So, I see three ways of resolving the problem that my changes caused for your > configuration. > > 1. [the easiest] Put zpool.cache loading instructions that used to be in > defaults/loader.conf into your loader.conf. This way everything should work as > before -- zpool.cache would be loaded from your boot pool. > > 2. Somehow (I don't want to go into any technical details here) arrange that > your root pool has /boot/zfs/zpool.cache that describes your boot pool. This is > probably hard given that your /boot is a symlink at the moment. This probably > would be easier to achieve if zpool.cache lived in /etc/zfs. > > 3. [my favorite] Remove an artificial difference between your boot and root > pools, so that they are a single root+boot pool (as zfs gods intended). As far > as I understand your setup, you use GELI to protect some sensitive data. > Apparently your kernel is not sensitive data, so I wonder if your /bin/sh or > /sbin/init are really sensitive either. > So perhaps you can arrange your unencrypted pool to hold all of the base system > (boot + root) and put all your truly sensitive filesystems (like e.g. /home or > /var/data or /opt/xyz) onto your encrypted pool. > ZFS is really flexible, you can use mountpoint and canmount properties to place > your filesystems from same or different pools into whatever file namespace > hierarchy you desire. Remember that your filesystem hierarchy in the mount > namespace does not always have to be the same as your ZFS dataset hierarchy. > > I hope that this makes sense to you. > If you have any additional questions, please do not hesitate. > > P.S. > ZFS/FreeBSD boot process is extremely flexible. For example zfsboot can take > zfsloader from pool1/fsA, zfsloader can boot kernel from pool2/fsB and kernel > can mount / from pool3/fsC. Of these 3 filesystems from where should > zpool.cache be taken? > My firm opinion is that it should be taken from / (pool3/fsC in the example > above). Because it is the root filesystem that defines what a system is going > to do ultimately: what daemons are started, with what configurations, etc. > And thus it should also determine what pools to auto-import. > We can say that zpool.cache is analogous to /etc/fstab in this respect. > > So I understand that my change causes a problem for a setup like yours, but I > believe that the change is correct. > +1 for zpool.cache on / (pool3/fsC in last example) -- Devin _____________ The information contained in this message is proprietary and/or confidential. 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