Level 9 dump size calculation?

[Jesse Guardiani]

Howdy list,

I've got a machine (4.6.1-RELEASE-p10) doing
level 9 dumps over SSH to a tape drive on a remote
machine over a T1.

The machine being backed up looks like this:

# df -h
Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/aacd0s1a   300M    52M   225M    19%    /
/dev/aacd0s1h   2.5G    11M   2.3G     0%    /tmp
/dev/aacd0s1e    12G   5.3G   5.4G    49%    /usr
/dev/aacd0s1f   5.8G   1.1G   4.2G    21%    /usr/home
/dev/aacd0s1g    12G   1.1G   9.6G    10%    /var
procfs          4.0K   4.0K     0B   100%    /proc

And my dump command looks like this:

ssh "$serverName" -nTc blowfish "/sbin/dump -0us 1000000 -f - /dev/aacd0s1a | gzip -c -3" | gunzip -cd -3 > "$tapeDriveDevice"

(machine with tape drive connects to machine to be
backed up via SSH, starts the dump on the remote
machine [with dump output piping through gzip and then
to stdout], decompresses output after it has traveled
over the T1 and finally writes it to the tape drive
device.)

I execute one dump command for /,/usr,/usr/home, and
/var.

And I get emailed output that looks like this:

  DUMP: Date of this level 0 dump: Tue Jan 13 06:00:01 2004
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/aacd0s1a (/) to standard output
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 54069 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: DUMP: 54091 tape blocks
  DUMP: finished in 130 seconds, throughput 416 KBytes/sec
  DUMP: level 0 dump on Tue Jan 13 06:00:01 2004
  DUMP: DUMP IS DONE

Granted, the above commands and output are from a level
0 dump, but my level 9s are performed in exactly the same
manner.

Here's my question:

How do I determine how large the dump output is?

The dump man page states that dump uses a blocksize of
10k by default.

54091 tape block * 10k/block = 540910k
540910k/1024 = 528.23M

Surely dump isn't expanding my 52M in / to 528.23M!!

However:

54091k/1024 = 52.82M (which is very close to how much used
space I actually have in /)

Is dump incorrectly labeling 54091 as the number of tape
blocks when it should instead be labeling 54091 as the
number of kilobytes?

-- 
Jesse Guardiani, Systems Administrator
WingNET Internet Services,
P.O. Box 2605 // Cleveland, TN 37320-2605
423-559-LINK (v)  423-559-5145 (f)
http://www.wingnet.net