lost inode, no backup

[Randy Bush]

FreeBSD ran.psg.com 10.0-CURRENT FreeBSD 10.0-CURRENT #4: Sat Dec 24 12:33:51 UTC 2011     root at ran.psg.com:/usr/obj/usr/src/sys/RAN  amd64

so doing all the wonderful holiday security upgrades and hit an ugly.
these two problems may not be related.

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problem one

on reboot, /usr/home was empty, as iff the inode had been lost.  but no
lost+found and fsck found no problem.

# df -H
Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/da0s1a    5.2G    1.6G    3.1G    34%    /
devfs          1.0k    1.0k      0B   100%    /dev
/dev/da0s1d    2.1G    356M    1.6G    19%    /var
/dev/da0s1e    2.1G    1.8M    1.9G     0%    /var/spool
/dev/da0s1f    138G    111G     15G    88%    /usr
/dev/md0       259M     36k    238M     0%    /tmp

and we know /usr/home was fine before the reboot as i was running out of
it, backup ran out of it, ...

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problem two

so i go for the local raid which is the target of the ever faithful
backup job, the essence of which is

# 4 - /usr
/sbin/dump 0Luaf - /dev/da0s1f | $SSH $USYS "/bin/cat > $DDIR/usr"

and which had run quite happily a few hours before

  DUMP: Date of this level 0 dump: Sat Dec 24 00:47:42 2011
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping snapshot of /dev/da0s1f (/usr) to standard output
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 56969906 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: 0.78% done, finished in 10:36 at Sat Dec 24 11:29:34 2011
  DUMP: 1.52% done, finished in 10:47 at Sat Dec 24 11:45:15 2011
  ...
  DUMP: 97.88% done, finished in 0:05 at Sat Dec 24 05:13:38 2011
  DUMP: DUMP: 56980137 tape blocks
  DUMP: finished in 15750 seconds, throughput 3617 KBytes/sec
  DUMP: level 0 dump on Sat Dec 24 00:47:42 2011
  DUMP: DUMP IS DONE

except that on all backups since the system moved to 10-current, home is
empty in the usr file!!!  all other directories there are good.

and we know /usr/home was good, see above.  the bleeping dump user has
its directory there.

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luckily i had other means of restoring.  but wtf?

randy