[comp.sys.sun] Dump parameters for QIC-150.

luis@bonito.tds.kth.se (Luis Barriga) (08/10/90)

We use a 150 Mbyte 1/4 inch cartridge tape Drive. The specification names
the following parameters:

	Data density: 10000 bpi
	Tracks           18 Track Serpentine
	length          600 ft.

When I perform a dump the following happens:

# /etc/dump 0csdtf 600 10000 18 /dev/nrst8 /dev/id000f
  DUMP: Date of this level 0 dump: Fri Aug 10 13:21:45 1990
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rid000f (/cm) to /dev/nrst8
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 298380 blocks (145.69MB) on 0.15 tape(s).
                                 ^^^^^^^      ^^^^^
  ........[stuff deleted]

The estimation shows only 0.15 tape(s), when it should say 0.9X
tape(s)since the capacity is approx. 150 MB.

Anybody got the right parameters?

+     Luis Barriga               +   The Royal Institute of Technology  +
+                                +     Dep. Computer systems (TDS)      +
+                                +          P.O. Box 700 43             +
+   e-address: luis@tds.kth.se   +       S-100 44 Stockholm             +
+                                +              SWEDEN                  +

fbresz@uunet.uu.net (08/14/90)

We use the following :

     dump 0cufs /dev/nrst24 1500 /dev/id000f

The moment I received the tape drive I of course had to know what the best
parameters to use for dumping were.  So I figured that the size parameter
is guessing feet. I figured since on a 60M tape the parameter was set to
600 (at least in 4.X, 3.X had some bizarre equation).  And the new drive
was 150M I would just change the size to 1500.  About 4 days latern our
Sun FE called to inform us that the best parameters for dumping were, in
fact, the same as we had established.

+--------------------+
|fbresz@ittc.wec.com |
|uunet!ittc!fbresz   |
|(412)733-6749       |
|Fax: (412)733-6444  |
+--------------------+