Re: Debian 8 and Debian 9 Dual Boot
- Date: Wed, 29 Nov 2017 06:50:38 +0000
- From: Michael Fothergill <michael.fothergill@xxxxxxxxx>
- Subject: Re: Debian 8 and Debian 9 Dual Boot
On 29 November 2017 at 03:15, Dan Norton <dnorton@xxxxxxxxxxxxxx> wrote:
On 11/13/2017 01:55 PM, Joe wrote:
On Mon, 13 Nov 2017 11:01:27 -0500 Dan Norton <dnorton@xxxxxxxxxxxxxx> wrote:Although I didn't say so, each install would have its own set of directories. Please say more about how to mount the other installation and share data. How to mount things in another volume group?Good advice so far, but to add a bit: all LVM groups will be seen at boot, and /dev will know about them. See man lvm2 and also here: https://wiki.debian.org/LVM for complete information about the commands you have available. There are also numerous tutorials on the Net which show basic usage of the simpler commands. It's worth having a look when you have some spare time, as one day you'll need to know some of this and won't have any spare time.
Reading the wiki reveals "Grub and ?LiLo are not compatible with LVM, so /boot should be outside the storage disk managed by LVM." Here's what I have:
Attempts to boot normally do not work. But using Super Grub2 on a bootable cd and selecting "Boot manually" and picking the hd1 entry brings up the jessie system that the installer reports as successfully installed on sda3. Using fdisk to take a look:
dan@debian8:~$ sudo fdisk /dev/sda
Command (m for help): p
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A615A904-0620-459F-BF44-
Device Start End Sectors Size Type
/dev/sda1 2048 411647 409600 200M BIOS boot
/dev/sda2 411648 16783359 16371712 7.8G Linux swap
/dev/sda3 16783360 151001087 134217728 64G Linux LVM
/dev/sda4 151001088 285218815 134217728 64G Linux LVM
/dev/sda5 285218816 419436543 134217728 64G Linux LVM
/dev/sda6 419436544 553654271 134217728 64G Linux LVM
/dev/sda7 553654272 1953525134 1399870863 667.5G Linux filesystem
Is there a problem here?
I have been using Supergrub for ages now. If you use Gentoo as I do you appreciate the irritation of continuous babysitting of grub2 every time
you reconfigure the kernel (e.g. after setting up the long winded nonsense required to make a firewall work properly) then grub tends to go awol
and requires TLC, massage therapy and soft music to start working properly.
Meanwhile you will feel so frustrated that you want to chew on barbed wire etc.
But supergrub is cool. It is like a bloodhound. You just can't fool it.
The more you use it the dumber you feel using grub2 until you have finally sorted the gripes and things have calmed down and stabilised - usually a month later.
Remember the scene from 2001 space odyssey where the monkey throws the bones up in the air.....
Do the same with grub2, then use supergrub until things work and then de-evolve again and vegetate in this area as I do.
dan@debian8:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/dm-0 9.1G 3.0G 5.7G 35% /
udev 10M 0 10M 0% /dev
tmpfs 775M 9.0M 766M 2% /run
tmpfs 1.9G 68K 1.9G 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda1 992K 142K 851K 15% /boot/efi
/dev/mapper/debian8--vg-var 8.2G 1.3G 6.4G 17% /var
/dev/mapper/debian8--vg-home 9.1G 356M 8.3G 5% /home
/dev/mapper/debian8--vg-tmp 268M 2.1M 247M 1% /tmp
tmpfs 388M 4.0K 388M 1% /run/user/115
tmpfs 388M 12K 388M 1% /run/user/1000
Doesn't this satisfy the statement that "/boot should be outside the storage disk managed by LVM" since it is on sda1?
Look in /etc/fstab for lines beginning /dev/mapper/[volume] which will be the volumes mounted in the running installation. The 'mapper' is turning LVM volumes into things which look like partitions for many purposes.
Here is fstab:
# /etc/fstab: static file system information.
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/mapper/debian8--vg-root / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda1 during installation
UUID=B07E-1F0B /boot/efi vfat umask=0077 0 1
/dev/mapper/debian8--vg-home /home ext4 defaults 0 2
/dev/mapper/debian8--vg-tmp /tmp ext4 defaults 0 2
/dev/mapper/debian8--vg-var /var ext4 defaults 0 2
# swap was on /dev/sda2 during installation
dbd0af037a23 none swap sw 0 0
/dev/sr0 /media/cdrom0 udf,iso9660 user,noauto 0 0
Why won't it boot normally, that is without using the bootable Grub2 cd?