Installing on Software RAID in new 18.04 server installer

Yes, Moshe there was a removal taking place some time ago. The Ubuntu bionic release notes indicate that in section Ubuntu Server (New since 17.10):

"f you require any of the following features in the installer, you will want to continue to use the alternate installer which can be downloaded from http://cdimage.ubuntu.com/releases/18.04/beta-2/: *LVM *RAID *multipath"

Reference:
https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes

The alternate installer is not available from that page. Where can I get it from?

It is not in the graphical installer for Ubuntu or Xubuntu. And I doubt it will be within the final ISOs for GUI based installers. I definitely know it won't be in Xubuntu 18.04. Therefore a normal setup is recommended and post-installation of mdadm and related packages.

As far as I know it will be available in some way for Ubuntu Server. You may therefore try http://cdimage.ubuntu.com/ubuntu-server/daily-preinstalled/ which contains pre-installed Ubuntu Server images. After copying the image to your disk apt-get can be used to install mdadm and setup of RAID.

By the way RAID via mdadm is fading out from GNU/Linux distributions since file systems like OpenZFS (ZFS 5000), HAMMER2 FS and B-treeFS include file system (driver) and RAID (controller) logic. Therefore the use B-treeFS on GNU/Linux is recommended over ext3/4 or even ReiserFS.

O.K. I just realized the alternate installer for Ubuntu (GUI) is not yet available, but any Ubuntu Server will do the job to setup RAID/LVM (via manual partitioning option).

As a workaround the Ubuntu Server ISO could be used to install the RAID and after installation Ubuntu (Desktop) to install using existing disks. That's a bit more work but will likely do the job.

Actually, it is not true that "any Ubuntu Server will do the job". The whole point of my asking this question in the first place was that the new Ubuntu Server installer does not support software RAID.

Further, I know that I can install on a single drive and then set up RAID using mdadm, but that's a real pain (because modifying the `/` mountpoint in 18.04 is harder than it used to be on older versions). The whole point of supporting RAID in the installer is to prevent needing this.

I agree, it (dmadm) should be available until the point where all Btrfs features are not only implemented, but thoroughly tested and stable. Other than that current Ubuntu Server ISOs should have the mdadm/RAID functionality. Are you sure its not there?

Look http://iso.qa.ubuntu.com/qatracker/milestones/389/builds/170803/testcases indicates the testcases Ubuntu Server amd64 testcases in Bionic Daily exist.

http://iso.qa.ubuntu.com/qatracker/milestones/389/builds/170803/testcases/1402/results contains Install (Default + LVM) in Ubuntu Server amd64 in Bionic Daily and more complex test

http://iso.qa.ubuntu.com/qatracker/milestones/389/builds/170803/testcases/1457/results Install (default + RAID1) in Ubuntu Server amd64 in Bionic Daily

Download ISOs at http://iso.qa.ubuntu.com/qatracker/milestones/389/builds/170803/downloads and for different architectures at http://iso.qa.ubuntu.com/qatracker/milestones/389/builds

@Moshe:

I guess you are using an ISO that uses the "new" server installer, like what is found here:

http://releases.ubuntu.com/18.04/

According to the above linked page:

"If you require LVM, RAID, multipath, network vlans, or network interface bonding during the installation; if you need to reuse existing partitions on your installation disk; or for support for other architectures besides AMD64/EM64T, see the alternative images location."

The "alternative images location" is found here:

http://cdimage.ubuntu.com/releases/18.04/release/

If I'm not mistaken, an ISO the uses "old" installer is downloadable from here:

http://cdimage.ubuntu.com/releases/18.04/release/ubuntu-18.04-server-amd64.iso