Have the device names for hard discs been changed?

[Christian Baer]

On Sun, 29 Jan 2006 19:12:39 +0000 (GMT) Gavin Atkinson wrote:

> I'm not sure it was ever 'e'.  I'm also confused by what you mean by 
> "dd-mode" - the footnote suggests you're talking about "dangerously 
> dedicated" mode, but the fact you created a slice and have "s1" in all of 
> your device names suggests that you are in fact not running in dangerously 
> dedicated mode.

Well, I never used a true partition table with FreeBSD. But since it
seems to cause problems I'll start with that now - if I can ever get
this to run, that is.

This disk you see here is now no longer dangerously dedicated The line
with the < was added..

>>  jon# ls -l /dev/ad6*
>>  crw-r-----  1 root  operator    0,  76 Jan 22 15:23 /dev/ad6
>>  crw-r-----  1 root  operator    0, 120 Feb  1 02:09 /dev/ad6a  <
>>  crw-r-----  1 root  operator    0,  93 Jan 22 15:00 /dev/ad6c
>>  crw-r-----  1 root  operator    0,  96 Jan 22 15:00 /dev/ad6cs1
>>  crw-r-----  1 root  operator    0,  92 Jan 22 15:00 /dev/ad6s1
>>  crw-r-----  1 root  operator    0,  94 Jan 22 15:00 /dev/ad6s1c

> What's the output of:

Ok, here goes... :-)

>   - fdisk /dev/ad6

jon# fdisk ad6
******* Working on device /dev/ad6 *******
parameters extracted from in-core disklabel are:
cylinders=310101 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=310101 heads=16 sectors/track=63 (1008 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 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 312581745 (152627 Meg), flag 80 (active)
        beg: cyl 0/ head 1/ sector 1;
        end: cyl 852/ head 15/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

Same goes for ad6a and ad6c

>   - fdisk /dev/ad6s1

jon# fdisk ad6s1
******* Working on device /dev/ad6s1 *******
parameters extracted from in-core disklabel are:
cylinders=310100 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=310100 heads=16 sectors/track=63 (1008 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:
<UNUSED>
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 0, size 50000 (24 Meg), flag 80 (active)
        beg: cyl 0/ head 0/ sector 1;
        end: cyl 1023/ head 254/ sector 63


>   - disklabel /dev/ad6

jon# bsdlabel ad6
# /dev/ad6:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a: 312581792       16    unused        0     0
  c: 312581808        0    unused        0     0         # "raw" part, don't edit


>   - disklabel /dev/ad6a and ad6c

jon# bsdlabel ad6a
bsdlabel: /dev/ad6a: no valid label found
jon# bsdlabel ad6c
# /dev/ad6c:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a: 312581792       16    unused        0     0
  c: 312581808        0    unused        0     0         # "raw" part, don't edit


>   - disklabel /dev/ad6s1

jon# bsdlabel ad6s1
# /dev/ad6s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  c: 312576642        0    unused        0     0         # "raw" part, don't edit
bsdlabel: partition c doesn't cover the whole unit!
bsdlabel: An incorrect partition c may cause problems for standard system utilities

> I wonder if somehow GEOM is getting confused and seeing it both as a 
> dd-mode disk, and as a normal disk?

Well, I'd say that's a big 'yes'. If I try to change anything with
fdisk, I get the error-message 'fdisk: geom not found'. This also
applies if I try to 'fdisk -BIv ad6'.


[device list del...]

> ... none of these other disks look like they are being used in dd-mode.

Well, they are, even if on an older system (FreeBSD 4.0 RELEASE). They
were formatted with that. Even if the system was updated up to the
latest STABLE 4, the drives were never changed.

> Traditionally, 'a' is root, 'b' is swap, and 'c' is the whole disk.  As 
> far as I know, they no longer have any special/implied meaning in FreeBSD 
> (other than 'a' on the boot disk), but the tradition of reserving a-c has 
> been retained for compatibility with other OS's.

Well, I coundn't find anything about a device ad6cs1d outside of RAIDs
or the like. What is going on here?

Regards
Chris