02-19-2005 03:13 AM
I am trying to figure out a way to erase disks on a HSG80 controllers based array and specifically looking for a command which does a true format. The data contained on the drives is not so critical that it requires a number of passes of writing 0s and 1s on every single block ;-) but perhaps a true format at a low level is enough.
I found the HSUTIL - format command - could not find any documentation though as in what it really does when it says "format" - is data really trashed? I know even with multiple passes of writing 0s and 1s, data can still be recovered - but as mentioned I am not concerned to that level - just after a genuine method to destroy data!
02-20-2005 07:23 PM
you could try putting all the disks you want to wipe into a stripeset, create a unit using that stripeset and run DILX in write mode on that unit. Just be careful what parameters you use with DILX.
Here's a customer advisory on how to use it:
You should set the unit to DISABLE=ALL and PREFERRED_PATH=THIS. The Unit must be online to the controller on which you run DILX. Also, do this during off-peak times, as it puts the HSG controller under a heavy load. Then you can delete the unit and stripeset when you're finished.
02-20-2005 07:36 PM
Yes had considered that. Do you have any literature on what DILX actually does in terms of erasing the disks, does it write 0s and 1s on every block? Basically, how does it perform a format?
HSUTIL - Format command seems a lot simpler and safer to run as you can select a physical device rather than DILX as you have to configure a set and a unit and it still places a whole lot of load on the whole array - Unfortunately I still do not have any piece of document that explains me what this command actually does.
I might end up logging a support call with HP.
02-20-2005 07:51 PM
How about setting the disks TRANSPORTABLE, presenting them to a Unix system and overwrting the raw device?
02-20-2005 08:12 PM
I have a Linux host sitting next to me and I could quite easily run badblock as many number of times as I want and this will do what I want. But if you have more than 30 disks, this procedure is less than pretty. Was wondering if there is such a thing at the controller end to achieve the same - in my opinion it would be a logical thing to have such a functionality or may be I am askin for too much!!!
Transportable (as you put it the other way) does not perform any format though...and the setting would be honoured by another similar HSG array, correct so that the data on the disk is also tranported across? A standalone host with a non-HSG controller, would it honour the "TRANSPORTABLE" tag on the disk, is this is a SCSI paramter?
02-20-2005 08:34 PM
TRANSPORTABLE is a term only valid in the HSG environment.
Setting an existing disk to "TRANSPORTABLE" on the HSG will update the SCSI disk's mode page to undo the meta data space reservation so the full capacity is available again.
It's been some time that I looked at this, but there were multiple 'counters' in this mode page to indicate the size of the disk and setting a disk "TRANSPORTABLE" made one of them smaller.
Sorry, I don't have more details handy, as this is usually only interesting for those who do program SCSI devices and that's not my job.