--- wikisrc/zfs.mdwn	2021/02/14 16:35:50	1.32
+++ wikisrc/zfs.mdwn	2021/02/17 17:25:45	1.33
@@ -109,6 +109,34 @@ areas to be included include:
   - disklabel partitions (e.g., /dev/sd0e)
   - wedges (e.g., /dev/dk0)
 
+Information about created or imported pools is stored in
+/etc/zfs/zpool.cache.
+
+## pool importing problems
+
+While one can "zpool pool0 /dev/wd0f" and have a working pool, this
+pool cannot be exported and imported straigthforwardly.  "zpool
+export" works fine, and deletes zpool.cache.
+
+"zpool import", however, only looks at entire disks (e.g. /dev/wd0),
+and might look at slices (e.g. /dev/dk0).  It does not look at
+partitions like /dev/wd0f, and there is no way on the command line to
+ask that specific devices be examined.  Thus, export/import fails for
+pools with disklabel partitions.
+
+One can make wd0 be a link to wd0f temporarily, and the pool will then
+be importable.  However, "wd0" is stored in zpool.cache and on the
+next boot that will attempt to be used.  This is obviously not a good
+approach.
+
+One an mkdir e.g. /etc/zfs/pool0 and in it have a symlink to
+/dev/wd0f.  Then, zpool import -d /etc/zfs/pool0 will scan
+/etc/zfs/pool0/wd0f and succeed.  The resulting zpool.cache will have
+that path, but having symlinks in /etc/zfs/POOLNAME seems acceptable.
+
+\todo Determine a good fix, perhaps man page changes only, fix it
+upstream, in curent, and in 9, before removing this discussion.
+
 ## mount order
 
 NetBSD 9 mounts other file systems and then ZFS file systems.  This can
@@ -126,13 +154,15 @@ zfs filesystems can be exported via NFS,
 
 The "zfs share" command adds a line for each filesystem with the
 sharenfs property set to /etc/zfs/exports, and "zfs unshare" removes
-it.  \todo Explain if /etc/zfs/exports is used and whether this makes
-any sense on NetBSD.
+it.  This file is ignored on NetBSD-9 and current before 20210216; on
+current after 20210216 those filesystems should be exported (assuming
+NFS is enabled).  It does not appear to be possible to set options
+like maproot and network restrictions via this method.
 
-On current as of 20210214, a remote mkdir of a filesystem mounted via
+On current before 20210216, a remote mkdir of a filesystem mounted via
 -maproot=0:10 causes a kernel NULL pointer dereference.  This is now
-understood and expected to be fixed very soon.  See
-[misc/55042](http://gnats.netbsd.org/55042).
+fixed.
+
 
 ## zvol