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Disklabelling a previously "used on linux" disk

Gary Hansford
Frequent Advisor

Disklabelling a previously "used on linux" disk

I have a problem on an rz29b that was previously used on a Linux system.

Tru64 will not let me erase the disklabel. The problem appears due to Linux having partitioned this disk (a to c) with none of the partitions starting at block zero... (type=resrvd8)

Any attempt at disklabel -rw or -z results in either "a partition is not block 0 of the disk" or "Open Partition would move or shrink...".

This looks to be a gotcha, Tru64 needs one partition to be at block zero for disklabel to work yet in this case cannot touch/edit the label because no partition starts at block zero.

Is there any way I can force Tru64 (tried v4 and v5) to ignore the partitions that are already there and relabel this disk. I've tried -e -z -wr and trying to add a new partition all get one of the error messages...

My guess is I'll have to take the disk to either an RA8000 or Linux Machine and erase the labels but thats a bit much - there must be some "sneaky" way of getting round this problem...

Cheers

Gary
10 REPLIES
Venkatesh BL
Honored Contributor

Re: Disklabelling a previously "used on linux" disk

This was something that always remained in the 'wishlist'. As far as I know, you need to go back to Linux and 'zero' the first few sectors using 'dd' and then come back to Tru64.
Ralf Puchner
Honored Contributor

Re: Disklabelling a previously "used on linux" disk

Why not simple use the DD command to overwrite the rawdevice of the disk?
Help() { FirstReadManual(urgently); Go_to_it;; }
Gary Hansford
Frequent Advisor

Re: Disklabelling a previously "used on linux" disk

This is the catch-22... even the raw device uses the partition table...

No partitions are pointed at block zero, therefore how can I get at block zero to erase the labels... !!

This is where I went wubble... and thought i'd ask the group !!

Cheers

Gary
Johan Brusche
Honored Contributor

Re: Disklabelling a previously "used on linux" disk


You can write over the disks boot/label area with the help of the console..

At the >>> prompt:

>>> chmod +w DKA* or DKB* or DKxnnn
>>> exer -a w DKxnnn &
>>> show_status

when it shows aro 8MB written, then init the system (or fg the exer and ctrlC)

__ Johan

_JB_
Johan Brusche
Honored Contributor

Re: Disklabelling a previously "used on linux" disk


Another way is with scu


/sbin/scu

scu> sbtl 4 3 0 <--- (disk on bus#4 target#3 )

scu> format


Also dd on the RAW special device should work

dd if=/dev/null of=/dev/rrzNNc bs=512 count=32

Replace /dev/rrzNNc by /dev/rdisk/dskNNc if on V5.1


___ Johan.

_JB_
Michael Schulte zur Sur
Honored Contributor

Re: Disklabelling a previously "used on linux" disk

Johan,

aren't the first 16 blocks read only?

Michael
Gary Hansford
Frequent Advisor

Re: Disklabelling a previously "used on linux" disk

Johan / All.

The SCU format command didn't work - message about file systems. The excer from SRM also failed with an error full of zeros...

Upshot was - Download the RedHat 7.2 ISO CD No1 image, Burn a cd-rom and then boot it. Run disk-druid / fdisk and erase the labels...

Thanks for the suggestions... was worth a try...

Cheers

Gary
hatasoymail.aria.com.tr
Occasional Advisor

Re: Disklabelling a previously "used on linux" disk


Hi;


/usr/lbin/zeero may help you.
mather
alex57
Established Member

Re: Disklabelling a previously "used on linux" disk

after some year...your response worked fine..many thanks....Alessandro from rome....
alex57
Established Member

Re: Disklabelling a previously "used on linux" disk

sorry i am referring to Johan ..prompt metod by exer!!!!!