Stuck in bootstrapping hell - how do I troubleshoot?

[Chris Zumbrunn]

On Apr 22, 2005, at 2:01 PM, Alex Zbyslaw wrote:

> Chris Zumbrunn wrote:
>
>>> The server is in a datacenter and I can only access it via ssh and 
>>> boot either from the local disks or via network (freebsd or linux) - 
>>> no serial console, so I can't see where it gets stuck during the 
>>> bootstrap.
>>>
> Do you mean that you can boot the machine from an OS it picks up from 
> the network?

Yes, exactly.

> I.e. you can boot some OS which is not the one of the local disk?  If 
> so, then boot the network FreeBSD, mount your local disks and look at 
> /var/log/messages.  If the machine was at least booting FreeBSD when 
> it died then you should see something.

I did check that. Nothing is written to /var/log/messages during a 
local boot attempt. So, the boot fails before that.

I checked the MBR by comparing the output of "dd if=/dev/ar0 bs=512 
count=1" on the trouble machines with that of a machine that boots fine 
- and they look identical. So, the MBR seems to be where it belongs.

I guess the boot process gets stuck either during boot1/boot2 but 
before the kernel loads or there is a problem with the RAID1 setup and 
the machine never even gets to the point where it would look for a MBR 
on the ar0 disks.

Also, when a debian disk image is installed on the same machine, it 
does boot from the local disks. So, maybe something is goofy with the 
partitioning/slicing - but I can't see what that would be.

# fdisk ar0
******* Working on device /dev/ar0 *******
parameters extracted from in-core disklabel are:
cylinders=14945 heads=255 sectors/track=63 (16065 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=14945 heads=255 sectors/track=63 (16065 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165,(FreeBSD/NetBSD/386BSD)
     start 63, size 240107427 (117239 Meg), flag 80 (active)
         beg: cyl 0/ head 1/ sector 1;
         end: cyl 1023/ head 254/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

# disklabel ar0s1
# /dev/ar0s1:
type: ESDI
disk: ar0s1
label:
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 255
sectors/cylinder: 16065
cylinders: 14945
sectors/unit: 240107427
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0

8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
   a: 240107427        0    4.2BSD     2048 16384    89  # (Cyl.    0 - 
14945*)
   c: 240107427        0    unused        0     0        # (Cyl.    0 - 
14945*)


Any further ideas or hints on what else to check would be very 
appreciated...

Chris