freebsd stable - Mar 2012 - problem: bsdlabel

hail,

I partitioned the disk this way:

 fdisk da0
******* Working on device /dev/da0 *******
parameters extracted from in-core disklabel are:
cylinders=12161 heads=255 sectors/track=63 (16065 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=12161 heads=255 sectors/track=63 (16065 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 166 (0xa6),(OpenBSD)
    start 126, size 20964699 (10236 Meg), flag 0
        beg: cyl 0/ head 2/ sector 1;
        end: cyl 280/ head 254/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 20971629, size 8379126 (4091 Meg), flag 0
        beg: cyl 281/ head 108/ sector 1;
        end: cyl 802/ head 254/ sector 63
The data for partition 3 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 29350755, size 41929650 (20473 Meg), flag 0
        beg: cyl 803/ head 0/ sector 1;
        end: cyl 340/ head 254/ sector 63
The data for partition 4 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 71280405, size 124086060 (60588 Meg), flag 80 (active)
        beg: cyl 341/ head 0/ sector 1;
        end: cyl 896/ head 254/ sector 63


but when was time to label it, I did it wrong:

bsdlabel -w da0

should have aimed slice 2

now, I just get da0 on /dev and sysinstall only sees da0 also. but fdisk sees it
all (as showed
above)

how can I erase all label info from da0 (not da0s1 or da0s2).

I tried to rewrite fdisk and all mbr info, but label info is still there.

I'd like not to have to reinstall OpenBSD, if possible.

thanks,

matheus

-- 
We will call you Cygnus,
The God of balance you shall be

A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?

http://en.wikipedia.org/wiki/Posting_style

Hi Matheus,

You have two options.

Option 1. Resync the in-memory and on-disk view of the world
Identify the device from 
# usbconfig list
Then power it off and then power on. If this doesn't work then you'll
need
to dd the device.

For example: 
# usbconfig list
ugen4.2: <DT Mini Slim Kingston> at usbus4, cfg=0 md=HOST spd=HIGH
(480Mbps) pwr=SAVE
# usbconfig -d 4.2 power_off
# usbconfig -d 4.2 power_on

Option 2. Clear the boot blocks 
# dd if=/dev/zero of=/dev/da0 bs=1M count=1
If this doesn't help then zero the whole device, omit the bs and count
arguments.

I'd also suggest that you assign 0xa5 to the device, by 
# fdisk -p da0 > /tmp/fdisk.cf
Use a text editor to change the 0xa6 to 0xa5; then write it back to fdisk
# fdisk -f /tmp/fdisk.cf /dev/da0

Of course, the excessive option is to reboot...
Regards, Dewayne.
PS I think this question would be better placed in the FreeBSD Questions
mailing list :)

On 28.03.2012 20:41, Nenhum_de_Nos wrote:
> hail,
> 
> I partitioned the disk this way:
> 
>  fdisk da0
> ******* Working on device /dev/da0 *******
> parameters extracted from in-core disklabel are:
> cylinders=12161 heads=255 sectors/track=63 (16065 blks/cyl)
> 
> Figures below won't work with BIOS for partitions not in cyl 1
> parameters to be used for BIOS calculations are:
> cylinders=12161 heads=255 sectors/track=63 (16065 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 166 (0xa6),(OpenBSD)
>     start 126, size 20964699 (10236 Meg), flag 0
>         beg: cyl 0/ head 2/ sector 1;
>         end: cyl 280/ head 254/ sector 63
> The data for partition 2 is:
> sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
>     start 20971629, size 8379126 (4091 Meg), flag 0
>         beg: cyl 281/ head 108/ sector 1;
>         end: cyl 802/ head 254/ sector 63
> The data for partition 3 is:
> sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
>     start 29350755, size 41929650 (20473 Meg), flag 0
>         beg: cyl 803/ head 0/ sector 1;
>         end: cyl 340/ head 254/ sector 63
> The data for partition 4 is:
> sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
>     start 71280405, size 124086060 (60588 Meg), flag 80 (active)
>         beg: cyl 341/ head 0/ sector 1;
>         end: cyl 896/ head 254/ sector 63
> 
> 
> but when was time to label it, I did it wrong:
> 
> bsdlabel -w da0
> 
> should have aimed slice 2
> 
> now, I just get da0 on /dev and sysinstall only sees da0 also. but fdisk
sees it all (as showed
> above)
> 
> how can I erase all label info from da0 (not da0s1 or da0s2).
> I tried to rewrite fdisk and all mbr info, but label info is still there.
> I'd like not to have to reinstall OpenBSD, if possible.
First of in the future you should use gpart(8) utility to manage partitions and
slices.
bsdlabel keeps metadata in the second sector. Therefore you should rewrite it to
destroy
label. But to be sure please show output of this command:

# gpart show

-- 
WBR, Andrey V. Elsukov

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