Does wiping a hdd when installing Ubuntu MATE also deletes BitLocker partitions?

Hi everybody,

A friend asked me to burn a DVD of a GNU/Linux distribution for her old Toshiba laptop with Windows Vista on it. She will copy her personal files to an external hard disk, and doesn't want to keep Windows, so she'll wipe the laptop's entire disk and install Ubuntu MATE 20.04.3 (as I'm familiar and like Ubuntu MATE that's what I'm going to burn and send via snail mail). She's a Windows user but doesn't have any GNU/Linux knowledge yet.

The thing is, she also has an encrypted partition created with BitLocker, and files on it that she'd rather be sure are erased. We're in different cities in France, and I won't have physical access to her laptop nor will I be able to ssh to her computer, and I haven't used Windows since XP, so I just wanted to make sure the BitLocker partition would also be gone for sure.

Would that be the case? Also, I'll happily take any and all advice to make things go smoothly for her.

Thanks in advance.

You can boot in TRY Ubuntu, use gparted to wipe out the disk, then INSTALL.

Maybe I am wrong, but when you install a new image and select the option that says something to the effect install and erase all content on the drive, the entire HDD/SSD is wiped clean for the new installation. :+1:t3::slightly_smiling_face:

Yes, when you select "Erase disk and install Ubuntu", that does delete all partitions on the disk, even encrypted partitions. However...

Deleting partitions does not mean erasing all data! Yes, after you delete the partitions, the data will be harder to access. But the only way to really get rid of sensitive data is to overwrite it and make sure it's overwritten. I like to use the shred command on hard disks which I want to eliminate data on.

If you really, really want to get rid of data on the hard disk, first find out the device name of the hard disk itself (usually /dev/sda on a laptop with no other internal hard disk drives and no SSDs). GParted can be useful for such a task, or you can go partway through the installer and it'll tell you what the device is, then back out of the installer.

When you're sure you've got the correct device, and you're sure you are willing to lose all data stored on that drive, you can use the command:

shred -vz [device]

This will wipe over the hard disk with random data three times, and then write zeroes to the drive so that applications will not complain about random data on the disk. The -v option will tell you the progress of the disk wipe, too.

Please note that this process can be time-consuming; depending on the age of the disk and its size, this process could be done in 15 minutes or it could take hours. Based on the impression I'm getting of the rough age of the laptop, I'd guess it takes about two hours to complete.

If you need the process to take less time, and you don't need three-letter-agency-grade data disposal :slight_smile: , then you can tell shred to make fewer passes with random data (or not to bother zeroing the disk afterward, since in my experience that's not strictly necessary):

shred -vn 1 [device]

This will overwrite the disk with random data only once (instead of three times), and will not zero the disk. This should take between 20-30 minutes to complete. If you want zeroing too, add the lowercase letter z between the v and the n in -vn.

I hope I didn't overwhelm you with information.

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Thank you for the replies, and thank you Gordon.

I was worried about BitLocker but now I have my answer, the partition will be deleted but the data can still be theoretically accessed until it's overwritten. The thing is, I promised my friend there wouldn't be any commands to type (she specifically asked), so instead of the shred command maybe I'll have to check a graphical tool like BleachBit to wipe free space after installation. Everything has to be as simple as possible -- The DVD will soon be on its way, I have a VirtualBox VM ready so we can do the install at the same time on the phone when it arrives.

I'm not familiar with Bleachbit (I prefer to use shred to wipe sensitive files, much easier) so I'll have to learn.

BTW, now that I have the entire specs of the machine I can say it's not a Toshiba but an Acer Aspire from 2009 with a whopping 250Gb hard disk (and Radeon graphics, no Nvidia, yay!).

Thanks again!

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