Hi, I have installed Slack 11 from DVD onto a Dell M70. My boot process is stalling at:
Detecting hardware: /etc/rc.d/rc.hotplug.start

The first errors to appear are:
ata: 0x1f0 IDE port busy
ata: 0x170 IDE port busy
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2
kmod: failed to exec /sbin/modprobe -s -k scsi_hostadapter, errno = 2

Then, after some further booting, I get
Detecting hardware: /etc/rc.d/rc.hotplug.start
and the system stalls.

I've googled these errors, but I haven't found anything that seems helpful. I can boot off the install DVD and mount the hard drive, but I'm not sure where to start diagnosing this problem.

You can boot your system by giving nohotplug on the command line (or by making the /etc/rc.d/rc.hotplug non executable).

Your problem is probably due to a bad module; you can blacklist modules that give problem in /etc/hotplug/blacklist. To know that guilty module you will have to proceed by trials and errors. Watch the output of dmesg, the content of /var/log/messages. You can see your loaded modules with the command lsmod

Well, I was at least able to get the system to boot by chmoding /etc/rc.d/rc.hotplug -- so thanks -- but I'm at a loss as to what values I should try blacklisting. I'm not sure what to look for in /var/log/messages and /var/log/dmesg ...

The last 2 lines in /var/log/messages are:
Oct 26 11:11:11 m70 kernel: cs: IO port probe 0x0a00-0x03af: clean.
Oct 26 11:11:11 m70 kernel: cs: IO port probe 0x0a00-0x0aff: clean.

The last 2 lines in dmesg are:
agpgart: no supported devices found.
scsi0 : SCSI host adapter emulation for IDE ATAPI devices

What exactly am I looking for?

I will try to suggest some hacks to find the culprit; let me know if it works.

1) give the option SHELLOPTS=xtrace at the kernel command line, before booting (if the entry on lilo is "Linux" type at the lilo prompt Linux SHELLOPTS=xtrace); and boot with hotplug enabled. This option will cause the shell to print out every command it tries to execute, with luch you will see the command that cause the hang; and you will be able to blacklist the wrong module.

2) Boot without hotplug and lauch it by hand afterwards :
sh /etc/rc.d/rc.hotplug start

When your system hangs; open another console and view the output of ps -A -F (the lines are cutted on the edsge of the terminal, best to type ps -A -F | less or redirect the output to a file. This list all command that the system are executing, normally you wil find the culprit.

If your see that the command that cause the hang is modprobe <something> or insmod <something>; then put <something> in /etc/hotplug/blacklist.

Thanks. I actually ended up solving the problem by running tail -f /var/log/syslog in one tty while manually executing /etc/rc.d/rc.hotplug in another. The culprit turned out to be ahci, and blacklisting it seems to work perfectly.

I don't quite understand what I've disabled by blacklisting ahci, but it is working.

Thanks bryankaplan. You helped me solve the same issue with Slak 11 on my Latitude 610


Dimi

Just as a little info...

You can get a internal description of a module by with
"modinfo <module name>"

It seems like AHCI has something to do with libata or ATA/SATA drives...