April 2009

More fun with mount points

Last fall I wrote about a mistake from years past where goofing up mount points on a filesystem could really cause some interesting side-effects. Well quite by accident I stumbled into a fun new way to blow up a system while working on yesterday's problems.

First a bit of background for those who are not familiar with UNIX style mount points. Before a disk is mounted on a UNIX system the place it will be mounted looks like a plain old directory. On OS X these directories are collected in /Volumes so there will be a set of directories here representing the various disks and the disks themselves will be mounted on top of these directories. So with disks named Ranch and Barn the directory looks like /Volumes/Ranch and /Volumes/Barn. It is with these directories that SuperDuper was off and running to replicate Ranch to Barn.

Trials and time machine

Twenty-four hours in it appears I now have a disk migration working. Usually it's a simple task. Unpack the machine and fire up Migration Assistant after going off to make and drink a few cups of coffee and presto the new machine is up and running.

Well that worked for the first many dozens of processors in the collection. This time, however it was not to be so simple. Each time Migration Assistant would run it would exit with the same error message.