FreeBSD slices and the Boot Manager
ataraxi at telia.com
Sun Jul 28 20:06:13 UTC 2013
Hi Warren and Polytropon,
A few minutes ago I booted up from a FreeBSD-8.4-RELEASE-amd64-memstick.img
to experience that it is sysinstall that is used in that release.
Next, I did a 'dummy' custom installation. And, as I supposed sysinstall
recognized disk ada0 as ad4 and disk ada1 as ad6. Then I aborted sysinstall
and rebooted in to my FreeBSD 8.3-Release.
Well, AHCI (Serial ATA Advanced Host Controller Interface driver) seems
involved when identifying disks and slices. But, only on newer computers
who has this option set to on in the BIOS. Maybe, bsdinstall in FreeBSD 9.0
and onwards can make use of AHCI directly.
When I bought this workstation and installed FreeBSD I thought something
was very much wrong with the wiring of the hardware/disks and I phoned
Dell's support ... without being much wiser.
My old Dell workstation on which I have used all the FreeBSD's from release
4.8 up to 8.0 I always got ad0 and ad1 as the disks in use. So, I had to
search the Internet for an answer why my new computer numbered disks oddly.
And I found your web page Warren
(http://www.wonkity.com/~wblock/docs/html/ahci.html) and I also read the
ahci man page. I also had to edit my /etc/fstab accordingly.
My FreeBSD 8.3 /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#
/dev/ada1s3b none swap sw 0 0
/dev/ada1s3a / ufs rw 1 1
/dev/ada1s3d /home ufs rw 2 2
/dev/acd0 /cdrom cd9660 ro,noauto 0 0
proc /proc procfs rw 0 0
linproc /compat/linux/proc linprocfs rw 0 0
Apropos labels, I only have two filesystems (+swap) on each slice, as I
only run a desktop workstation. I do that following Greg Lehey's advise in
his book "The Complete FreeBSD" 4th Edition.
More apropos labels: The latest BIOS version 2.4.0 for Dell T1500 does not
support UEFI/GPT/GUID. As far as I know, Dell only have the Unified
Extensible Firmware Interface on its PowerEdge servers.
(The reason why I want to merge two slices into one big ada1s1 is the need
for more disk space for FreeBSD 8.4 and keep 8.3 as it is, but then as
> On Sun, 28 Jul 2013, Warren Block wrote:
> On Sun, 28 Jul 2013, Polytropon wrote:
>> On Sat, 27 Jul 2013 19:39:30 +0200 (CEST), Conny Andersson wrote:
>>> 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
>>> disk 1?
>> I'm not sure I'm following you correctly. The sysinstall program
>> is considered obsolete, the new system installer is bsdinstall.
> AFAIK, sysinstall is still used in FreeBSD 8.X, and bsdinstall does not have
> a boot manager option anyway.
>>> 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
>>> of the install.)
> Sorry, I don't understand this at all. AHCI should not be involved with
> identifying slices.
>> That is a _good_ consideration! To make sure things work independently
>> from "boot-time recognition", use labels for the file system and then
>> mount them by using the labels. Encode the OS version number in the
>> labels, so it's even easier to deal with them. Use "newfs -L" on
>> un-mounted partitions (you can do that from the install media).
> For existing filesystems, that would be tunefs -L. And agreed, filesystem
> labels make relocation much easier.
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