h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'm preparing some old Macintoshes to be given away. Since they're going to the IT s in another department, we have to be sure all the data are gone, as there are some sensitive documents on some of them.

So does anyone have an idea how to zero a hard drive under OS 9? I've tried looking for shareware programs, but there don't seem to be any sites offering them that are still up

Try the OSS community? I found a good windows one from there, but has no mac version.

What about trying the harddrive manufacturer? They often have low level utilities that'll do this.

Failing that you could google it - there's various sites out there that seem to offer guidance.

There's only one safe way to 'zero' a hard drive, whether Mac or Windows.
Remove said drive, place on concrete floor and apply a 14lb sledgehammer at full swing several times!!
As well as software available to do this zeroing technique there is an equal amount of software available that can undo it as well.
Hard-drives being cheap these days the safest, secure method is replacement and just put on the basic operating system.

I'd love to take a hammer to it, or demagnetise it. Unfortunately, the University won't let us do that. It has to be passed on to the IT students.

And since they use our old computers the same way medical students use cadavers, I think they'll be looking for things... Haven't found a Mac utility. Or did find one, but it was in BinHex

Maybe just throw everything out, then fill the whole hard drive with huge, neutral video or audio or picture files and delete those again?

I think you just have to be aware that whatever software method you use there is likely to be some way round it.
I fitted a second hand hardrive on my brothers pc just a few weeks ago and when I fired the pc up I discovered 'hidden files'. Further checks showed they were empty initially till I used a small utility program that actually then revealed bank details and statement details of the previous owner of the pc the drive originally came from. It's nigh on impossible to permanently remove data once written to a hard drive.
I think the majority of IT folk will say that the safest method is as I said earlier.
Passing these used pc's to IT students, well, that's a challenge they'll not resist I'd have thought.

there is software that can undo the more usual zeroisation techniques, but the best stuff is only really undone by the sort of hitech stuff forensics labs have. nothings completely gone for ever, of course, even a lump hammer won't sort it totally and new forensic techniques mean even demagnetising it isn't the be-all and end-all. But these recovery techniques are not widely available, often use pretty hi end specialist hardware to sort it and cost a packet.

To be fair though, if it is going to the IT students to use, don;t worry. Within half a day they'll have managed to mangle them somehow anyway!

"then fill the whole hard drive with huge, neutral video or audio or picture files and delete those again?"
This is essentially what the more pedestrian erasers try to do. The cleverer ones try to use binary strings for the overwritting. The really clever ones use randomised multi pass binary strings so that the pattern of data overwritting the original is not predictable and the multi passes (USA DOD recommend 7 passes, but it ain;t enough) ensures the underlying is even more mangled.

Ok, so it looks fairly hopeless anyway. I might as well ask the IT guys what I can do so they can't read it

If the macs can boot from cd, you could possibly use the 'dd' utility, which is available on many Linux live cds, including DSL, or Puppy linux

The command is something like: dd if=/dev/zero of=/dev/

Also check out 'darik's boot 'n nuke'. Depending on the hardware, there may be a flavour that will work on a mac.

http://dban.sourceforge.net/

Hmm. I might have to resort to that, because the professor can't remember his password, anyway

try the legal route

as you say there are sensetive files on the drive get the legal department to draw up a complicated non discloser agreement and reams and reams of paperwork that the recipient and end users have to sign....along the lines of the official secrets act....the people getting the computers will probably tell you to "shove it" and keep the computers.....

We don't have any law students.

Anyway, we *want* the direct-recycling method, letting someone else use it.

But since we don't know the password either, I'll probably end up formatting the entire drive "from the outside" a few times - anyone know a good program?

The IT students plan to use it for a server, anyway, so I don't have to preserve the OS.

Passwords aren't required to dd a hard drive. It works 'from the outside'

If you can boot the machine from a linux live cd, you're in!

If the machine is set up to priority boot from the hard disk, you'll have to invoke the BIOS setup, and change boot priority to CD-ROM.

If the BIOS is locked with a password, you can probably reset the CMOS by either shorting across some pins, or by removing the battery for 10 minutes

That's the question, whether a Mac will boot from a Linux CD, I've never tried that before

But there won't be any changes in the standard settings, really, unless someone who didn't know what they were doing played with it, always a possibility.

Computers aren't this institute's strong suit. When I arrived a few years ago, the secretary still had a Win 95 machine that had never been defragged! I got it running fast and now they all think I'm some kind of computer whisperer

Some they will, and some they won't, and some you just can't tell

Check here: http://www.livecdlist.com/?pick=Linux_PPC&showonly=All&sort=&sm=1

Gentoo would be my choice

Presumably it's the administrtors who are saying they have to be passed on. The type of people who have no knowledge of anything aprt from what they have picked up on the courses the spend their time on.

I suggest you throw the problem back at them. Tell them to find software to zero a hard-drive and you will happily pass them on.

Since they have given the rule they must have looked into the problems and solved them....

No point wasting your time otherwise say the 14lb sledgehammer is the only way to keep your sensitive information safe.

A nice catch 22 situation for them.

Hi Mal

You should have asked this over at the Orchard at A690653. Some of us Mac geeks and evangelists hang out there!

I found this on the UK Apple website http://discussions.apple.com/thread.jspa?messageID=6611345&#6611345 but you don't say what the Macs are so it may not be as useful as it could be.

turvy

Thanks.

The Powers That Be simply want us to throw the computers away. We are morally opposed to this

But since the s up on the main campus hoard all the installation CDs, we can't use those... *sigh*

Could some one please explain why 'the s' always seem to make life 10times more difficult to do anything with computers?

The amount of control they have over what people who actually *do* work on pc's wastes so much money and time that if they just fixed the sodding things like they are supposed to we would have less stress and a better workload all round...rant over...

If TPTB want you to throw them away why don't you give them to a charity that recycles them to the Third World or something?

http://www.oxfam.org.uk/get_involved/recycle/computers.html
http://www.recycle-more.co.uk/nav/page1768.aspx
http://www.recyclenow.com/

t.

We'd have to be even more careful about erasing data.