Grub, lvm and encryption

dartfira · 2014-11-26 09:58:52

Yesterday I thought the problem on my brand new encrypted archlinux system was the encrypted part, then in the night I realize: if grub didn't show up the problem belongs here nor in dmcrypt, luks or lvm.
So today I'm checking up the partition to see if there are some mistake, got two partition sda1 and sda2, the second one is a LVM the first one a Bios partion EF02 where grub2 is, Gpt scheme has been used. The mkconfig goes smooth, except for lvmeta error the guide also mention it. So where is the problem, does the system didn't recognize grub partition, I think so, or it should be somewhere else?
Where can I check the startup log?
When the computer star grub doesn't show up and the system reboot in a loop, I see only the Asus logo then nothing, that's because ipthef problem is the grub loading nor the encrypted partition, I thought that because it didn't found the lvm volume reboot itself then I realize that I should be seeing grub anyway.

I've been using this guide for the whole installation https://wiki.archlinux.org/index.php/Dm … VM_on_LUKS

Last edited by dartfira (2014-11-26 10:02:39)

CarlD · 2014-11-26 11:05:11

Some of the information you've provided is somewhat confusing. Is your system UEFI or BIOS based? If BIOS, then you have no reason to use a GPT partition table. It should be MBR. This could be why Grub isn't even showing up.

I suspect you are trying to take on too much at this juncture, and so are in for a world of frustration. My advice would be to first learn how to install Arch properly (including building relevant knowledge about partition tables, partitioning, and bootloaders such as Grub). Once that is sorted, then build on that knowledge by learning the basics of LVM. And then once you know how to install Arch with LVM, then go for LUKS.

dartfira · 2014-11-26 19:41:59

Maybe I've made a mistake understanding the difference for mbr and gpt but I've been an arch user for 4 years.

TheSaint · 2014-11-26 20:06:15

Even mkinitcipio should have some relevance, I think. Start to see grub lvm and luks.

teateawhy · 2014-11-27 01:49:20

You have two partitions, sda1 is EF02 and sda2 is LVM, but where is your separate boot partition that is required for full system encryption?

dartfira · 2014-11-27 09:40:48

Only the lvm partition is encrypted.

Last edited by dartfira (2014-11-27 10:37:54)

clfarron4 · 2014-11-27 09:51:36

@dartfira: OK, so what I understand from this thread so far is:

1) You have an installation with LVM on LUKS;
2) You have chosen to use a GRUB BIOS bootloader with GPT. Hence an EF02 partition, as per these instructions here;
3) You haven't created a separate /boot partition (separate to the EF02 partition) so you can actually boot into the LVM on LUKS installation.

Assuming those three points (specifically the last one) are correct, you need to either shrink /dev/sda2 or re-install, creating a third partition (100MBshould work for most people) which should be mounted as /boot in the arch-chroot environment (so there needs to be three disk partitions. Creating /boot as a logical volume won't work here).

Addendum: I didn't think to mention the option of using a USB Stick as a /boot partition, because I assumed you wouldn't want to have to put in USB Stick every time you booted everytime you want to get to Arch. The plus of this option is that you don't need to resize anything, but you might need to format the USB stick to an accepted filesystem for the bootloader and you need to install the bootloader to the disk.

Last edited by clfarron4 (2014-11-27 10:15:54)

dartfira · 2014-11-27 10:41:14

Or I can use the other disk, the one in the CDROM port, to add a boot partition, is it correct?
So the lvm partition, with luks, will be the only one on the ssd and the other disk (I use it for storage) will have a boot partition on it.

teateawhy · 2014-11-28 21:37:02

Yes, it is possible to have the /boot partition on another disk. I have my /boot partition on a usb flash drive. May i ask why you want to have /boot on another disk?

Last edited by teateawhy (2014-11-28 21:37:19)

dartfira · 2014-11-29 13:17:23

Because it's insecure to have a disk half encrypted and half not, so I decided too have the uncreypted boot partition on another disk.

clfarron4 · 2014-11-29 15:03:20

So, you'll be looking at using a LiveCD to chroot into the installation, mounting the memory stick at /boot and installing the bootloader to that.

teateawhy · 2014-11-29 19:49:29

Before installing the bootloader you need to copy the initrd and kernel over to the boot partition. Reinstall the linux package after mounting the boot partition to let pacman do it for you. Also you can delete the files from the /boot directory on the root partition.

Arch Linux

#1 2014-11-26 09:58:52

Grub, lvm and encryption

#2 2014-11-26 11:05:11

Re: Grub, lvm and encryption

#3 2014-11-26 19:41:59

Re: Grub, lvm and encryption

#4 2014-11-26 20:06:15

Re: Grub, lvm and encryption

#5 2014-11-27 01:49:20

Re: Grub, lvm and encryption

#6 2014-11-27 09:40:48

Re: Grub, lvm and encryption

#7 2014-11-27 09:51:36

Re: Grub, lvm and encryption

#8 2014-11-27 10:41:14

Re: Grub, lvm and encryption

#9 2014-11-28 21:37:02

Re: Grub, lvm and encryption

#10 2014-11-29 13:17:23

Re: Grub, lvm and encryption

#11 2014-11-29 15:03:20

Re: Grub, lvm and encryption

#12 2014-11-29 19:49:29

Re: Grub, lvm and encryption

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