Read Sun's tapes to IRIS?

[Dave Olson]

In <BILL.91Apr21174321 at inls1.ucsd.edu> bill at inls1.ucsd.edu (Bill Reynolds) writes:

| In article <1991Apr19.210809.26153 at eng.umd.edu> naiming at eng.umd.edu (Naiming Shen) writes:
| > I have two questions. first, the IRIS manual say there is two types
| > of archive: cpio and tar. When I use system manager tool(on IRIS 4D/310)
| > there is only tar can be used. I don't know why.
| > Second, I have a tape from Sun workstation(I don't know what format that
| > is) and I want to read it into IRIS, but the IRIS couldn't read it.
| > Can somebody tell me what kind of format the IRIS can read? I was told
| > I can change some switchs in a configuration file for tar, what is the
| > file, how can I change it?
| > Thanks in advance.
| 
| We had to solve the inverse problem, i.e. read sgi tapes onto a sun.
| We were successful with the following command:
| 
|     dd if=/dev/nrst<tape device #> of=<path of output file> conv=swab
| 
| This will create a binary image of the first file from the tape on the
| disk. Subsequent calls will put the next tapefile on the disk (be sure
| to change the name of the output file or you will overwrite it). An
| sgi service rep told me that he successfully used this to read Sun
| tapes onto an sgi. good luck.

Assuming you know the tape format (cpio, tar, bru, etc), then the
most likely problem is indeed byte swapping.  When creating QIC
tapes for use on non-SGI systems, or reading QIC tapes made on
non-SGI systems, try using the non-byte swapping device.

Assuming you have only tape drive, the byte-swapping device is
/dev/tape, the non-swapping device is /dev/tapens.  The devices
in /dev/rmt/* have the suffix 'ns' if they are non-swapping.

The ns devices are also slightly faster, since the byte swapping
is done in software.  The default of byte-swapping was done to be
compatible with the older 68K based SGI systems, which had a tape
controller that byte-swapped the data.

None of this is normally needed with the non-QIC drives, since the
/dev/tape link is then normally made to the ns device, since there
are no compatiblity issues there.
--

	Dave Olson

Life would be so much easier if we could just look at the source code.