Date: Thu, 15 Jun 1995 19:46:28 -0700 (PDT) From: Poul-Henning Kamp <phk@ref.tfs.com> To: hackers@freebsd.org Cc: faq@freebsd.org, doc@freebsd.org Subject: disk handling program Message-ID: <199506160246.TAA03119@ref.tfs.com>
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There has been a lot of questions about disks and what to do.
The situations isn't quite optimal in 2.0.5/current and hopefully somebody
will get/take time to remedy this before 2.1.
Presently we take a very conservative position on geometry, and it is
ABSOLUTELY CRUCIAL that the "bios-geometry" is correct/sensible.
For your boot-disk it MUST be correct. For other disks it merely have
to make sense.
There are two ways to get it right:
A: Create a msdos partition, and delete it from FreeBSD.
B: Boot freebsd with -v and look at the "bios-geometry" table
it prints at the end, find the right one for this particular
drive and use that.
In the meantime:
For those of you who really feel adventurous, you can
cd /usr/src/release/libdisk
make tst01
./tst01 wd0
tst01 is a small driver program for the libdisk library, it's pretty much
the same as the undocumented wizard mode in the sysinstall program.
ALL GUARANTEES ARE OFF if you run it (well, we don't give any in the first
place).
It will NEVER write to the disk unless you ask it to.
(If there is a curses-programmer with extra time at hand, please make
a decent userinterface to this please. Contact phk@freebsd.org.)
In particular if you send email with questions/complaints, it is very
helpful for us if you can include the output from tst01 in the email.
The output could look like this:
ref# ./tst01 sd0
--==##==--
Debug_Disk(sd0) flags=0 bios_geom=675/128/32
boot1=0x0, boot2=0x0, bootmgr=0x0
--> 0x15040 0 2766300 2766299 sd0 whole 0x00
--> 0x15080 0 32 31 - unused 0x00
--> 0x150c0 32 2764768 2764799 sd0s1 freebsd 0xa5 C=
--> 0x15100 32 65536 65567 sd0s1a part 0x07
--> 0x151c0 65568 65536 131103 sd0s1b part 0x01
--> 0x15200 131104 65536 196639 sd0s1e part 0x07
--> 0x15240 196640 1024000 1220639 sd0s1f part 0x07
--> 0x15280 1220640 1544160 2764799 sd0s1g part 0x07
--> 0x15140 2764800 1500 2766299 - unused 0x00
Column Explanation
--------------------------------------------------------------------------
1 The arrows show at what level this chunk of disk lives.
All chunks must fit inside exactly one higherlevel chunk.
2 Pointer. This is the pointer inside the tst01 program. You pass
this to the delete command: "delete 0x151c0" for instance.
3 Offset. Where on the disk the chunk starts. Can be negative
for the Ontrack'ed disks.
4 Length, numbers of 512bytes sectors in chunk.
5 End, number of last sector in chunk.
6 Name. "X" means that no meaningful name can be assigned.
7
whole
represents the entire disk
unused
space presently without a name of it's own. Some unused
chunks are reserved.
freebsd
FreeBSD slice
dos
MSDOS slice
part
FreeBSD partition
extended
Extended dos partition
8 Subtype. For things which live in the MBR (freebsd,dos,extended)
this is the MBR type field. For things in a FreeBSD slice, this
is the disklabel type.
9 Flags
C FreeBSD compatibility slice.
A Active
= Aligned
> Extends past cyl 1023
R marked as 'root'
B marked as using bad144
--
Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox.
whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc.
Just that: dried leaves in boiling water ?
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