Debugging the <code>ftape</code> driver

# 5 Debugging the `ftape` driver

Contents of this section

## 5.1 The kernel/`ftape` crashes on me when I do `...' - is that a bug?

No, that is a feature `;‐)`

Seriously, reliable software do not crash. Especially kernels do not or rather should not crash. If the kernel crashes upon you when you are running `ftape`, and you can show that it is `ftape` that is messing things up, regard it as a Bug That Should Be Fixed. Mail the details to Bas (`<bas@vimec.nl>`) and to the tape channel.

## 5.2 `ftape` keep saying `... new tape', what do I do?

[You cannot do this anymore; I do not know a way of fixing it]

To get rid of this, do this (blindfold): login as root and say ``rmmod ftape`'. `ftape` should choke a few times, give three segmentation violations (or so), and give up life.

Check the activity LED on your floppy drive (you do have one, don't you?). If it is constantly lit, you have turned the floppy cable upside down somewhere. Check your cable between controller, tape drive and floppy drive. Usually, one (or more) of the connectors have been turned upside down, such that pin 1 in one end connects to pin 34 in the other end. (All the even-numbered pins are grounded, so you wont be able to use your floppy either). Don't worry; this cannot damage your hardware.

## 5.3 OK, it's a bug ...ehhh... feature - How do I submit a report?

First, make sure you can reproduce the problem. Spurious errors are a pain in the ass, since they are just about impossible to hunt down :-/ This is a quick check list:

- Kernel version, and patches applied (even `ftape` patches)
- `ftape` version
- tape drive model / manufacturer
- What you did to expose the problem
- A log of the run with tracing level set to 7
- What went wrong on your system.
- Do not delete the kernel and the `ftape.o` file. We may want you run try some patches out or run a different test on your system.

Increase the tracing level to 7 (just below maximum tracing) and run the offending command again. Get the tracing data from the kernel log or `/proc/kmsg`, depending on where you harvest your error messages. Do not try to `trim' the kernel log. You might consider something irrelevant, which is essential to the investigator of the bug. State exactly what you did, and what happened on your system. We might not see the error because we use a different tape drive or another version of the kernel!

Send your bug report to `<linux-activists@niksula.hut.fi>` (and remember to add a ``X-Mn-Key: TAPE`' line in the header). You should also mail the bug to `<bas@vimec.nl>`.

## 5.4 How do I change the trace-level?

You can do this two ways: either change the default trace-level (the var ``tracing`' in file ``ftape-rw.c`') and recompile or say

> `

>             mt -f /dev/ftape fsr <tracing-level>

> `

The use of the `fsr` command in `mt` is a hack, and will disappear with time.

## 5.5 When I use `/dev/nftape`, I get garbage ... why?

This was a problem in `the old days', before version 0.9.10. Nowadays, the non-rewinding devices are working. If you have anything earlier, I strongly recommend you to update to the 1.13b version.

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