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I have three ssd's (ssd0, ssd1, ssd2). ssd0 and ssd1 have Ubuntu 18.04 installed on them via this procedure in the Ubuntu installer:

Erase disk and install Ubuntu

  • (checked) Encrypt the new Ubuntu installation for security
  • (checked) Use LVM with the new Ubuntu installation

That means I have full disk encryption, LVM and grub2 on ssd0 and ssd1 like this (output from lsbulk):

ssd0:

sdb                       8:16   0 447,1G  0 disk  
├─sdb1                    8:17   0   512M  0 part  /boot/efi
├─sdb2                    8:18   0   732M  0 part  /boot
└─sdb3                    8:19   0 445,9G  0 part  
  └─sda3_crypt          253:0    0 445,9G  0 crypt 
    ├─ubuntu--vg-root   253:1    0   445G  0 lvm   /
    └─ubuntu--vg-swap_1 253:2    0   976M  0 lvm   [SWAP]

ssd1:

sdc                       8:32   0 447,1G  0 disk  
├─sdc1                    8:33   0   512M  0 part  /boot/efi
├─sdc2                    8:34   0   732M  0 part  /boot
└─sdc3                    8:35   0 445,9G  0 part  
  └─sda3_crypt          253:0    0 445,9G  0 crypt 
    ├─ubuntu--vg-root   253:1    0   445G  0 lvm   /
    └─ubuntu--vg-swap_1 253:2    0   976M  0 lvm   [SWAP]

ssd2 has win10 installed on it.

Both grub2 bootloader (grub2 on ssd0 and grub2 on ssd1) recognize win10, but both grub2 bootloader do not recogize the other Ubuntu installation.

Why is that and how can I make it work?

The desired configuration would be that I still have a seperate grub2 on ssd0 and ssd1 and both should recognize the other Ubuntu (as well as win10) such that I can remove ssd0 or ssd1 and still have a a bootloader for the Ubuntu/win10 dualboot. When ssd0, ssd1 and ssd2 are connected, then I simply set in the BIOS which bootloader to use, wheter the bootloader from ssd0 or the one on ssd1.

Some probably necessary information:

  • UEFI BIOS
  • Partition scheme is GPT
Ini
  • 430
  • Do not know LVM, but others have posted they need the LVM drivers (which you have) and then have to manually mount the LVM to be seen in current install. Then run sudo update-grub But if you have same name/label will that create confusion? – oldfred Oct 06 '18 at 14:48
  • What you mean with "same name/label"? – Ini Oct 06 '18 at 21:13
  • You have two of these: ubuntu--vg-root Do not know if that is an issue or not. – oldfred Oct 06 '18 at 22:37
  • When I'm not using full disk encryption on ssd1, then I can find the Ubuntu on ssd1 via os-prober and update-grub executed on ssd0's Ubuntu. That means the full disk encryption is the issue. Probably a bug? I mean you'd probably want to also find encrypted volumes via os-prober and update-grub. – Ini Oct 07 '18 at 02:49
  • @oldfred: I don't think so – Ini Oct 07 '18 at 02:49
  • You can add a grub stanza to 40_custom to chain load to the other grub. Then it handles boot on other drive. See configfile example: https://askubuntu.com/questions/344125/how-to-add-a-grub2-menu-entry-for-booting-installed-ubuntu-on-a-usb-drive You can use label or UUID. – oldfred Oct 07 '18 at 03:38
  • Does this also work when the two Ubuntu drives are both encrypted? – Ini Oct 07 '18 at 11:19
  • Never in last 10 years seen anyone with two encrypted Linux systems, so you are the one testing whether it works or not. I think it might as configfile type entries are like booting, or grub it just switching boot to other system. If /boot inside LVM and encrypted it may have .mod files for that or not, never checked. – oldfred Oct 07 '18 at 13:45
  • @oldfred Why does this matter? Even when you have one non-encrypted and one encrypted you should have the option do decide wheter you want grub2 on A or B – Ini Oct 07 '18 at 15:55
  • I do not think it matters, have you tried it? I have multiple Ubuntu installs & a Fedora. But boot from one grub, turn off os-prober as I still have old installs I have not erased, so they are not needed in grub and add my own boot stanza in 40_custom. – oldfred Oct 07 '18 at 19:28

0 Answers0