FreeBSD slices and the Boot Manager

Conny Andersson ataraxi at
Sun Jul 28 20:04:33 UTC 2013

Hi Peter,

I need much more disk space for the FreeBSD 8.4-RELEASE, so I will need the 
space of the two 'old' slices.



> On Sun, 28 Jul 2013, Peter Andreev wrote:

> Why wouldn't you simply update your 8.1 to 8.4?
> 2013/7/27 Conny Andersson <ataraxi at>
>> Hi,
>> I have a workstation with two factory installed hard disks. The first
>> disk, ada0, is occupied by a Windows 7 Pro OS (mainly kept for the three
>> year warranty of the workstation as Dell techs mostly speak the Microsoft
>> language).
>> Instead I have configured the BIOS to boot from the MBR on the second disk
>> as I most of the time (99%) use FreeBSD. The MBR on ada1 was installed with
>> sysinstall's option "Install the FreeBSD Boot Manager", when I installed
>> the FreeBSD 8.3-RELEASE.
>> (The latest BIOS version 2.4.0 for Dell T1500 does not support
>> The second disk ada1, now has three FreeBSD slices:
>> 1) ada1s1 with FreeBSD 8.1-RELEASE
>> 2) ada1s2 with FreeBSD 8.2-RELEASE
>> 3) ada1s3 with FreeBSD 8.3-RELEASE
>> I want to install the new FreeBSD 8.4-RELEASE on ada1s1 by overwriting the
>> now existing two first slices. This means that ada1s3, must become ada1s2
>> instead. Is this possible to do?
>> A very important question is if sysinstall's option "Install the FreeBSD
>> Boot Manager" detects that I have a FreeBSD 8.3 and detect it as slice 2 on
>> disk 1? So it becomes a boot option when I am rebooting? (Maybe the slice
>> may come up as ad6s2, because AHCI in FreeBSD 8.4 isn't enabled at the time
>> of the install.)
>> If the answer to these questions is yes, then the next two questions arise.
>> Can I mount ada1s2a (FreeBSD 8.3) from the newly installed FreeBSD 8.4 and
>> edit my FreeBSD's 8.3-R /etc/fstab according to the new disk layout, and
>> occasionally run FreeBSD 8.3 without problems? Or do I have to do more to
>> get it to work?
>> The idea behind this kind of 'reverse' disk layout of mine is to have
>> FreeBSD 8.4 as my new default OS. And have FreeBSD 8.3 untouched for
>> configuring FreeBSD 8.4 and booting into it when ever needed. If I can do
>> this as described above, I will have plenty of space on the disk for the
>> future and a new FreeBSD release.
>> Thanks for your interest in my questions,
>> Conny Andersson
>> =-=-=-=-=-=-=-=-=-=
>>   Conny Andersson
>> <ataraxi at>
>> =-=-=-=-=-=-=-=-=-=

More information about the freebsd-questions mailing list