Arg: no mdadm on Ubuntu 18.04.5 Desktop install disk?

[Robert Heller]

At Mon, 4 Jan 2021 00:56:25 +0100 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> So, install Server and then just do `apt install xubuntu-desktop` or
> something like that. It's easy enough; I've done it a lot in my
> experiments to build a GNUstep-based (and ROX Desktop-based) remix.

This does not work either.  The server ISO starts the RAID arrays and starts 
the LVM volume group, but the installer does not give me any option to use the 
existing RAID or LVM, but only gives me the option to create new RAID and/or 
LVM volume groups.  Is there some special magic to get the *installer* to see 
the *existing* RAID and LVM?

This is what my disk structure looks like:

sauron.deepsoft.com% cat /proc/mdstat 
Personalities : [raid1] 
md0 : active raid1 sdb2[0] sda2[1]
      1003904 blocks [2/2] [UU]
      
md1 : active raid1 sdb3[0] sda3[1]
      1952118784 blocks super 1.2 [2/2] [UU]
      bitmap: 2/15 pages [8KB], 65536KB chunk

unused devices: <none>

md0 is the /boot file system (CentOS 6 uses Grub1, which does not understand 
LVM) 

md1 is a LVM volume group:

sauron.deepsoft.com% dir -lL /dev/mapper/
total 0
crw-rw----. 1 root root  10, 58 Jan  7 09:50 control
brw-rw----. 1 root disk 253, 11 Jan  7 09:50 sauron-c632guest
brw-rw----. 1 root disk 253, 12 Jan  7 09:50 sauron-c664guest
brw-rw----. 1 root disk 253,  1 Jan  7 09:50 sauron-c6_root
brw-rw----. 1 root disk 253, 14 Jan  7 09:50 sauron-c764guest
brw-rw----. 1 root disk 253,  6 Jan  7 09:50 sauron-distrocds
brw-rw----. 1 root disk 253,  5 Jan  7 09:50 sauron-dvdisos
brw-rw----. 1 root disk 253,  7 Jan  7 09:50 sauron-extra
brw-rw----. 1 root disk 253, 18 Jan  7 09:50 sauron-gollumC7boot
brw-rw----. 1 root disk 253, 17 Jan  7 09:50 sauron-gollumC7root
brw-rw----. 1 root disk 253,  2 Jan  7 09:50 sauron-home
brw-rw----. 1 root disk 253, 13 Jan  7 09:50 sauron-localrepo
brw-rw----. 1 root disk 253, 15 Jan  7 09:50 sauron-msbuilder
brw-rw----. 1 root disk 253,  8 Jan  7 09:50 sauron-SourceManagementC5
brw-rw----. 1 root disk 253,  4 Jan  7 09:50 sauron-Stuff
brw-rw----. 1 root disk 253,  0 Jan  7 09:50 sauron-swap
brw-rw----. 1 root disk 253,  9 Jan  7 09:50 sauron-ub1204_32
brw-rw----. 1 root disk 253, 10 Jan  7 10:06 sauron-ub1204_64
brw-rw----. 1 root disk 253, 19 Jan  7 09:50 sauron-ubuntu_root
brw-rw----. 1 root disk 253, 16 Jan  7 09:50 sauron-videoholding
brw-rw----. 1 root disk 253,  3 Jan  7 09:50 sauron-wine

I would like to install Ubuntu 18.04 onto sauron-ubuntu_root, leaving 
everthing else alone.


I guess I need some other install hack.  What are my options?  I suppose I 
could swap in a spare disk and install there and then copy it over and 
manually hack the boot setup...  I would really avoid that, since it is such a 
pain.  (I don't know, but installing Slackware from a shoebox full of floppies 
was actually easier.)

It appears that Ubuntu is looking like a much harder to deal with O/S than I 
thought...

-- 
Robert Heller             -- Cell: 413-658-7953 GV: 978-633-5364
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