Very Computer

Hi.
        I was wondering if it was possible to do a "low level" format
on IDE drives on an ultra 5. When i run the format command , select a
drive and tell it to format the drive it says it cant. I would like to
wipe the discs clean. Is there anything i can do?

Thanks (btw, merry christmas)

A LLF to wipe a drive clean is inappropriate even for SCSI drives.
LLF has side-effects which you probably want to avoid.

If you simply want to remove the bootstrap and partitioning information
all you need to do is zero the first 1K on the drive. Do something like
this:

    dd bs=1k count=1 < /dev/zero > /dev/rdsk/c0t0d1s2

If you're concerned about making confidential information unrecoverable,
then whatever you do (including a LLF) is *NOT* guaranteed to always
wipe out all your old data.

To be absolutely certain no one can recover your old data you have to
do what the goverenment does with its old disk drives, you have to
physically destroy the disk.

If you merely want to make a best effort at wiping out the old data
than you can simply zero the whole drive. Do something like this:

    dd bs=64k < /dev/zero > /dev/rdsk/c0t0d1s2

Another method is to use the format command's analyze/purge function.
That gets most of the data but it specifically doesn't wipe out any
sectors that were automatically replaced by alternates due to I/O
errors detected by the drive's firmware. For some drives there isn't
any utility that lets you wipe out all the possible "bad" sectors
which can have (multiple) copies of your data.

Quote:> A LLF to wipe a drive clean is inappropriate even for SCSI drives.
> LLF has side-effects which you probably want to avoid.

What side-effects? Due to the SCSI specification a LLF cant harm the drive
or render it unusable. The only thing is that when a LLF gets interrupted
(i.e. power loss) its highly possible that the drive cant be used until
another complete LLF has been done. And due to the EIDE and ATA
specification a LLF even cant harm a EIDE- or UDMA-disk. The only HDs that
answered to a LLF with dead were some old IDE drives with sizes smaller than
540MB....

Quote:> If you're concerned about making confidential information unrecoverable,
> then whatever you do (including a LLF) is *NOT* guaranteed to always
> wipe out all your old data.

Thats right. Even after a couple of LLFs the data can be restored if You
have access to an ultra-clean room, special tools and if You have the
knowledge. Data Rescue Labs are doing this, but You pay a very very high
price fo that! If You just want to be sure that the data cant be restored
by some tools available at home or from the net a LLF is a very good and
secure way...

Benjamin