multi-boot (fixed)

doug doug at
Wed Oct 19 20:19:22 UTC 2011

> On Wed, 19 Oct 2011, Lowell Gilbert wrote:
>> doug at writes:
>>> On Wed, 19 Oct 2011, Lowell Gilbert wrote:
>>>> doug at writes:
>>>>> I have a system with two physical disks with a version of FreeBSD
>>>>> installed on each disk. With various 7.x systems I had:
>>>>>   F1 disk1 on slices ads5x
>>>>>   F5 disk2 on slices ads6x
>>>>> I installed 8.2 on disk2, incorrectly saying leave the mbr alone. So
>>>>> when I boot from the second disk I get
>>>>>   F6 PXE
>>>>>   Boot:  F1
>>>>> I can then hit F1 or wait and all goes okay. I tried using sysinstall
>>>>> to rewrite the FBSD boot manager but that not effect any change. Must
>>>>> I rewrite the mbr on disk 1 also?
>>>> That's what I would expect to have to do...
>>> Pre 8.2 the behavior the selected system just boot without the extra
>>> message. I had a 7.0 and a 7.4 system installed. I replaced the 7.4
>>> system with 8,2 With the boot setup I understand the FreeBSD boot
>>> manager would be on sector 0 track 0 of disk 1. The boot record for
>>> disk 1 is in the first logical sector for the drive. The boot record
>>> for disk 2 should be similarly placed on disk 2.
>>> What I think is missing is putting the boot manager on disk 2. If that
>>> is the case, is there a way to do that without reinstalling?
>> boot0cfg(8) from the system that does boot.
>> Or boot in "rescue" mode from a CD (or other removable media)
>> and use sysinstall.
> thanks

This is a classic cast (I think) of RTFM. Thanks for hanging in with me. The 
correct answer is install the standard boot record on disk 2. I think I can 
interpert the handbook that way. I did this with sysinstall as my second attempt 
at boot0cfg seriously broke the system on disk 2. boot0cfg is left to me as 
homework. This is a case where I may be able to get from the code what I could 
not from the man page.

I do not know if part of the different is the BIOS has raid0 build in which 
almost works. I just turned this off giving me two test systems.

More information about the freebsd-questions mailing list