DEC 7000 Model 750

[James Monroe]

How do I format the drives? Wipe them clean?

[James Monroe]

Found answer elsewhere. But how do you know the data is gone?

[labadie_1]

When is the data gone ?

If you hope it is gone: $ init drive:
more serious: $ init/erase drive:
really serious: take a hammer and...

if you have security concerns, I think the hammer is the only answer in my opinion.

[James Monroe]

I have do the command on a couple of drives but I don't see the volume label changing? What I am really asking is how do I see the drive in question?

DOS way "Dir" nothing appears in filesystem.
VMS way "?"

[James Monroe]

After doing the command I get this:

%SYSTEM-F-DEVMOUNT, device is already mounted

[John Gillings]

James,

"Erasing" data can be tricky. There are people out there with equipment that can retrieve data from disks that have been overwritten several times. So it depends on how erased you want your data to be. If you want to make sure that the data is truly inaccessible, even to highly determined and clever people with unlimited budgets, then you need to go even beyond Gerard's hammer. The platters need to be shredded and incinerated (and some levels of security even require the ashes to be disposed of securely!)

As you have discovered, the simplest mechanism is DELETE/ERASE. This is a single pass, overwriting the data with zeroes.

See "OpenVMS Guide to System Security" Section 8.9.5.1.

Note the manual refers to SYS$EXAMPLES:DOD_ERAPAT.MAR - a program to generate secure erasure patterns, implemented as a system service. Since this example doesn't seem to be present on OpenVMS Alpha distributions, I've included it as an Alpha self extracting saveset - just RUN it on an OpenVMS Alpha system to unpack. Note I have NOT tested building the routine on OpenVMS Alpha, and eyeballing the code, I suspect that some changes are necessary - beware! Also note that you have to write the program to do the actual erasure - this routine just generates the patterns. Fastest and simplest implementation would be to do a spiral write to all LBN's using IO$_WRITELBLK (requires LOG_IO privilege).

There may be freeware available "out there" to do this already, but beware! by the very nature of the task, you'll want to be very sure that any software you use for this task isn't a "trojan horse" designed to steal the information you're trying to erase!

[Martin P.J. Zinser]

First show dev d should give you a list of all disk drives on the system.

If the disk you want to erase is mounted first unmount it (dismount /system), then init/erase,
remount the disk and check that there is no data on there.

As noted earlier, if you want to be really really sure the data is gone you might need to heat the disk (sans plastic cover) above the Curie point or dissolve the platters with an appropriate acid.

[Ian Miller.]

some recommend INIT/ERASE multiple times - I don't know if that is better than INIT/ERASE once. For normal security this is OK. For higher levels then secure physical destruction is the only accepted method. It depends on your requirements.

[Bradford Hamilton_1]

>After doing the command I get this:

>%SYSTEM-F-DEVMOUNT, device is already mounted

James,

You must dismount the drive first before initializing it.

--Brad

[James Monroe]

I wondered if I needed to dismount the disks. Ok, thanks for the response.

What is the command to view the info on the disk again?

Also if init is enough to just rid my system of data then that is enough to bring this system off line.

If someone wants to get at the data later we have tape.

[Ian Miller.]

to summerize earlier responses

to dermine which disk - display list of devices starting with the letter D
SHOW DEV D

select the apppropriate disk and dismount
DISMOUNT Dxxxxx

Allocate the disk (to prevent anybody else from remounting etc)
ALLOC Dxxxxx

Clear the disk - takes quite a while as everblock on the disk is written
INIT Dxxxxx /ERASE

Deallocate the disk
DEALLOC Dxxxxx

[James Monroe]

You RULE! Thank you...

Anyone what to buy a Dec 7000 Model 750?

[John Gillings]

re Ian:

>some recommend INIT/ERASE multiple times - I don't know if that is better than INIT/ERASE once

INIT/ERASE writes zeros to the drive. Writing a known and predictable pattern, doesn't change the magnetic remnance left by the old data, so multiple passes are no better than a single pass at obscuring the data (some drives/controllers may even avoid re-writing identical data - be suspicious if the second and subsequent passes complete faster than the first).

An even greater complicating factor is RAID and virtualisation - who's to say that there aren't other copies of your data elsewhere? What about replaced bad blocks? Finding and rethreading all the pieces is probably a more difficult problem than reading remnance, but if the data is valuable enough, and the "EVE" has sufficient budget...

This is really splitting hairs, as the cost of disk space these days is probably less than the cost of the person time it would take to perform and verify the erasure, so physical destruction is the most certain and cost effective way to really destroy data.

[James Monroe]

Did I mention that we are dealing with a cluster system that has shadow drives and these commands aren't working as stated.

How do I break the connection between a two node system then remove the shadow drives the init the data off of the drives?

[Martin P.J. Zinser]

Well in that case you need to dismount/cluster.
The init et al. stays the same.

You will need to init the shadow set members separatly.