A Win8 "slave" disk is using "UEFI secure boot"

ghost123uk · 08-14-2015, 09:02 AM

OK, getting so many residents in our area to migrate to various flavours of Linux, all good

A few days ago I was asked to install Linux on an Acer laptop which had it's BIOS set to UEFI secure boot. No problem, I took the HDD out, fitted a another (spare) one, turned it back to legacy boot and installed Mint17 = all good.

However, I needed to copy the users files. On connecting up the original drive as a USB slave, the fact that the Windows 8 had been installed using UEFI secure boot setting meant my new Linux build could not read the data. Fortunately the original drive still booted (after re-setting to UEFI) so I was able to dump the users files onto a stick, then copy them to the Linux build that way.

~~~~~~~~~~~~~~~~~~~~~

Question = If that Windows 8 drive could not boot (damaged O.S.), is there any way I can get a "Live CD" or my "Persistent" PenDrive Linux build to read a Windows slave that has been built with UEFI?

michaelk · 08-14-2015, 09:55 AM

Did you try mounting the windows NTFS partiton? If so what were the errors?

Windows 8 uses a fast boot mode where the system actually "hibernates" versus actually shuts down when you turn the computer off. This puts the filesystem in an unsafe state unless you perform a full shutdown. If you want to dual boot and access the windows data you should disable fast boot. However, you should be able to mount the drive read only in case Windows 8 can not boot.

linux does support UEFI (distribution specific) for a while now with a few (I do not know the exact number) distributions that even support secure boot.

ghost123uk · 08-14-2015, 10:49 AM

Quote:

Originally Posted by michaelk

Did you try mounting the windows NTFS partiton? If so what were the errors?

Ah, err, no, I didn't try to manually mount it because I'm used to external drives "auto mounting" when I plug them into the Linux builds I use.
Perhaps I should have tried to mount it

Quote:

Originally Posted by michaelk

Windows 8 uses a fast boot mode where the system actually "hibernates" versus actually shuts down when you turn the computer off. This puts the filesystem in an unsafe state unless you perform a full shutdown. If you want to dual boot and access the windows data you should disable fast boot. However, you should be able to mount the drive read only in case Windows 8 can not boot.

Aye, ta for that, I did a proper full shut down of the Win 8 build before removing it physically from the machine. Also, just to be clear, I was not doing a dual boot but fitting another drive for the Linux build and connecting the Win8 drive as a USB slave, just to copy personal data off it.

Quote:

Originally Posted by michaelk

linux does support UEFI (distribution specific) for a while now with a few (I do not know the exact number) distributions that even support secure boot.

Ummm, just puzzling over why my normal Mint 17 live CD did not automatically "see" the Win8 drive, though as said ^^^, I didn't consider using G-Parted or summat to look for it and manually try to mount it. I wonder if that would have worked.

EDIT = I still have her Win8 drive here on the bench. I just connected it up, via USB, to my (Linux 17) machine and G-Parted says it is unallocated

I'm not sure what UEFI does to an Win8 NTFS file system <blush>

Thanks for the input

michaelk · 08-14-2015, 11:27 AM

The drive will not automatically mount due to the error generated by the file system being in an unsafe state. I do not know what happens when using gparted.

In a nutshell UEFI is a replacement for the legacy BIOS firmware which is the firmware that boots the computer. The last thing it does is pass control to the boot device's ( i.e. hard drive, usb drive, optical disk etc ) boot loader. The main advantage is it allows booting from a drive > 2TB.

https://en.wikipedia.org/wiki/Unifie...ware_Interface

ghost123uk · 08-14-2015, 11:37 AM

Thanks again for the further input

Would you know why my normal LM14 DVD would not attempt to boot in that Acer whilst the BIOS was set to UEFI ?
(Booted fine when set to Legacy).

EDIT = Sorry, I meant LM17

michaelk · 08-14-2015, 11:57 AM

I don't know. There were problems with LM14 using EFI on some laptops.

ghost123uk · 08-15-2015, 02:47 AM

Quote:

Originally Posted by michaelk

I don't know. There were problems with LM14 using EFI on some laptops.

Sorry, I don't know why I typed LM14, I meant LM17

Edit = I just found this =

Quote:

My first guess is that you've got a 32-bit (i386) version, which won't be bootable in EFI mode on a 64-bit computer

From here = http://askubuntu.com/questions/21043...-uefi-bootable

So it looks like that is the answer.

273 · 08-15-2015, 06:50 AM

Does Mint automatically install NTFS drivers? If not then that would explain the drive not auto-mounting. Also, it's likely that the drive has multiple (I'm guessing 4 or so) partitions if it's an OEM Windows install and drives with multiple partitions, in my experience at least, don't tend to auto-mount.

ghost123uk · 08-15-2015, 07:28 AM

Quote:

Originally Posted by 273

Does Mint automatically install NTFS drivers? If not then that would explain the drive not auto-mounting. Also, it's likely that the drive has multiple (I'm guessing 4 or so) partitions if it's an OEM Windows install and drives with multiple partitions, in my experience at least, don't tend to auto-mount.

In my experience, the LM17 Live CD does automatically mount any drives it finds, even ones with multiple partitions. I often use this to copy users personal files from their old Windows build to their new Linux O.S.

It seems my "problem" as in the OP, was due to the Acer I was working on being a 64 bit machine and I was using a 32 bit Linux DVD. I am guessing (from what I have read elsewhere) that if I had used a 64 bit Linux DVD, it would have coped with the UEFI and the 64 bit, booted fine and displayed the users files. The next time I get a UEFI / 64 bit machine on the bench, I will test that theory