Chapter 4. Known Problems and Solutions

Table of Contents

4.1. Introduction
4.2. SCSI difficulties
4.3. Installer dies during install with the error: Error on SCSIRead(), #5
4.4. Boot hangs while recognizing ethernet or video card
4.5. Problems with Mkfs 1.4 recognizing the last partition on the drive

4.1. Introduction

This section is not for bugs. It is for things such as system limitations that might have work-arounds.

4.2. SCSI difficulties

Many users have reported filesystem corruption under NetBSD. Symptoms include mysterious hangs and the transformation of numerous files from executable binaries into device files. The problem seems to plague Quantum drives more often than other models. This problem only happens on '030-based Macs using the ncrscsi driver.

Although this problem is technically a bug in the ncrscsi driver, it does have a workaround. The solution is to change to a kernel using the sbc SCSI driver instead. One of these kernels is available from:

4.3. Installer dies during install with the error: Error on SCSIRead(), #5

The most recent version of the Installer (1.1g as of this writing) still has difficulties with partitions on large drives (i.e. greater than 1GB in size). The problems seem to occur most often on Quantum Fireball drives (I don't believe that it is limited to them), but the key factors seem to revolve around having partitions (often large partitions) located on the upper portion of the disk (i.e. beyond the first 1GB of the disk) and writing large distribution sets to these partitions (smaller sets often complete, but the base distribution set will often die). A similar bug in the Installer was fixed a while ago, but this one appears to be slightly different.

There are a few workarounds. The first thing to try is to increase the amount of memory allocated to the Installer to as much as you can give it. The next thing to try is to move your NetBSD partitions to the start of the drive (or as close to it as possible). If this doesn't work, you'll need to install as many distribution sets as you can using the Installer, then use the Installer's Mini-Shell to copy in the distribution sets to your NetBSD partition, and finally finish installing the sets from within NetBSD.

4.4. Boot hangs while recognizing ethernet or video card

This problem is usually a result of a conflict between ethernet and video cards. One possible solution is to simply reorder the cards in their slots. If this does not work, try removing whichever card you cannot live without and see if the boot sequence stops hanging.

If you're boot sequence is hanging merely because of a video card, chances are the kernel is not yet properly clearing the interrupts for your card. There is a HOWTO for locating the information necessary for doing this:

With the proper information, changes can be made to the kernel to allow your machine to boot without having to remove the card.

4.5. Problems with Mkfs 1.4 recognizing the last partition on the drive

The symptoms of this problem are that you have created a partition of whatever type that you want to convert into a NetBSD partition, but Mkfs 1.4 refuses to recognize the partition.

This problem is caused by an off-by-one error in the Partition Map which is created by several hard drive formatters (including the latest HD SC setup from Apple). Basically, the number of Partition Map entries is one greater than the reported size of the Map. Mkfs 1.4 ignores this last entry (and rightly so, since it might be the Driver Partition in a correctly formatted drive).

The solution is to upgrade to Mkfs 1.45 or later where this bug is fixed. If you cannot locate Mkfs 1.45 or later, you have two choices. You can either use a formatter which correctly writes the Partition Map or else you can place a small partition at the end of the disk. If you are going to keep a Mac OS partition around, this is an excellent place to put one. On the other hand, if you'd rather conserve space, a 1 kB Scratch partition at the end of the disk should also work.