About dd (ghost HPUX OS)

[Kevin.Wang]

I have no mirrordisk software ,my vg00 is on /dev/dsk/c1t2d0 (18GB), be afraid that this disk is corrupted,I want to backup the OS to another 18GB disk (/dev/dsk/c2t2d0).

Can I use the command 'dd' ?
How should I write the command line?

Thank in advance.

[Karthik S S · Accepted solution]

Yeah you can use dd to duplicate the disk.

Boot in to single user mode (recommended bcoz u will have less number of open files),

dd if=/dev/rdsk/c1t2d0 of=/dev/dsk/c2t2d0 bs=1024k

Regards,
Karthik S S

[Mark Grant]

Yes, you can do this but I'm not sure it's the best way. You would be better off using the disk space for something nice and doing regular Ignite backups to tape.

If this disk goes, and you have no mirror, your machine is going to die. In order to get it back how it was, you are going to have to do a re-build and Ignite is best for that.

[Hoefnix]

Hi,

If you think your disk is corrupted, I would not like to boot to Single User mode (it migth not come up at all).
What you can do is create an Ignite Tape (try install the IgniteUX software if not installed yet, it does not need a reboot)
Put DDS tape in tapedrive
run:
make_tape_recovery -ACvid /dev/rmt/0mn

Change devicename to your DDS tape device.

After you created the recoverytape you can recover this on the other disk.

If above is not possible (for example no tapedrive) you can use the suggested dd option)

HTH,
Peter

[Kevin.Wang]

dd if=/dev/rdsk/c1t2d0 of=/dev/rdsk/c2t2d0 bs=1024k

I try it,and it proved to be right.
After it runs completely,I shutdown the machine. then replace the disk c1t2d0 with c2t2d0,and the new disk can bring the OS to startup.

Thank you ,everyone.

[Trond Haugen]

Depending on what is corrupt on your root disk I would not reccomend dd for making a new bootable disk as it would at best copy the problem. Ignite/UX as suggested is a good alternative. If you go for the dd version I would reccomend a Ignite backup too. Just to be on the safe side.

Regards,
Trond