Format an Hard drive under HP-UX

[Yan Berube]

I need to send back some WS to a supplier. How I can erase all data on each hard drive quickly ? Do we have a somethings in unix like "format c:" in wintel ?

Thanks

[Jeff Schussele]

Hi Yan,

Yes - the mediainit command.
But it's not recommended for drives you wish to keep, however, nor for drives with especially sensitive data as there are more secure techniques.
Commands would be like:

mediainit /dev/rdsk/cXtYdZ

Note the need for the raw device.

man mediainit for details

Rgds,
Jeff

[Steven Sim Kok Leong]

Hi,

Another way is to erase the data is to dd the /dev/dsk/c?t?d? with zeros etc e.g.

# dd if=/dev/zero of=/dev/dsk/c1t2d0 bs=1024

Hope this helps. Regards.

Steven Sim Kok Leong

[MANOJ SRIVASTAVA]

writing a string at the start of the hard disk will do the job

cat < file name > > /dev/dsk/c0t0d0 will write the file at the start of the disk hence invalidating the format , you can also use mediainit to do the same.

Manoj Srivastava

[David Ritchie]

mediainit performs a low-level (i.e. at the SCSI level) format. For most people, this is sufficent.

dd'ing over the front of the disk is not sufficent - if you have confidential data on the disk, bad guy could do something like

dd if=/dev/dsk/c1t0d0 bs=4k | strings | grep '[0-9]*-[0-9]'

to look for phone numbers and social security numbers (as an example) on the disk ....

even mediainit'ing is not completely secure - if bad guy takes the mechanism to a data recovery facility, they can often recover data by reading each of the tracks 'off-center' of the primary servo data... not trivial, not impossible either. Multiple
mediainits make this less likely to be successful.

It really depends on your level of paranoia. The military does not throw away drives at all - the drives are just ran through a crusher when the equipment is obsoleted...

-- Dave Ritchie

[Stefan Farrelly · Accepted solution]

You want this; it writes random numbers from 1 to 255, all you do is add a pipe then dd of=/dev/rdsk/cxxxxx to write random numbers to the entire disk until it ends.

perl -e 'srand(time() ^ $$); while (1) { print int(rand(1)*256); }'

[David Ritchie]

Hi, can you assign points to this thread and close it out if it answer your question? Thanks...

-- Dave

[Yan Berube]

Thanks !