How to install the Ubuntu Operating System on a Dell OptiPlex PC with RAID

This article provides information about the Ubuntu 16.04 operating system and Dell's OptiPlex Desktop systems, using the Intel Matrix RAID setup.

Table of Contents:

1. Introduction
2. Installing Ubuntu on a VHD (RAID 1 or 0)
3. Rebuilding RAID with Ubuntu installed
4. Option for Extended Display missing in RAID installed Ubuntu

Introduction

Ubuntu 16.04 and the type of RAID used on our OptiPlex desktops is not a natural fit. The OptiPlex uses Intel Software to provide a version of RAID 1 or 0. Ubuntu is not set up by default to recognize this sort of RAID. Various issues branch off from this original issue. While you can upgrade to the latest LTS version, the OptiPlex series of desktops have been certified for use with Version 12.04 through to 16.04. Below we will give information and links to workarounds and various installation steps to get around this RAID issue.

Note: Are you still having issues? You may want to reach out to the experts on one of the forums listed at the bottom of the article. The Linux community is your best resource for out of the usual software issues. Dell Only supports Ubuntu that comes installed on the PC. This information is provided for your information, but is used at your own discretion.

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Installing Ubuntu on a VHD (RAID 1 or 0)

Ubuntu cannot be installed on a VHD (RAID 1 or 0) with the default setting of the partition table that Ubuntu uses. When you set up a RAID configuration under the Intel Matrix Manager (Pressing the CTRL+I function before boot.) and then start the machine from the Ubuntu LIVE media and start the installation. You will get an error on the next step Ubuntu cannot be installed on this partition.

Instead you need to set up the RAID partitions using the Intel Matrix Controller Interface and then carry on with the rest of the instructions below.

Start by configuring your Software RAID. Go to the Canonical article linked below and follow the instructions from the start of the article until it gets to the Bootloader Section:

• Installation/SoftwareRAID 

In order to work around this issue, you need to change the default setting to /dev/mapper/xxxxxxxx_Volume1 and set up the swap, Boot, and EXT4 partitions manually. Check out the article below on how to change this setting:

• Installing Ubuntu Server with Intel Matrix RAID arrays

Check out the guides below for more information about custom Ubuntu Installs:

• Installing Ubuntu on your Dell PC
• Create multiple custom partitions while installing Ubuntu
• The types and definitions of Ubuntu Linux Partitions and Directories Explained

Note: If you have completed the installation and there are any issues, the easiest and quickest resolution is to run the install again.

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Rebuilding RAID with Ubuntu installed

Previously because the platform does not support VHD, the system fails to rebuild RAID1. If you replace one of the two hard drives, the system would remain on rebuild status. If you reset the new hard drive in the RAID controller interface by pressing the CTRL+I function before the system boots. Which forces the rebuild, it does not work. The RAID1 volume remains on rebuild status.

Note: I say RAID1, as you can only recover from a mirrored setup. RAID0 is quicker as it is striped, but has no fault tolerance capability.

However, if we say that you have used the correct methods to install (As recommended in Section 2.) Ubuntu with the latest BIOS. Then we recommend the following steps to resolve or test this particular issue:

1. In order to recreate a fault, we can remove a hard drive from the array and reboot the machine.

2. The first thing is to check the system boots in degraded mode.

3. When in degraded mode there is only one hard drive active in the RAID1 group (most commonly md0). Where sdX is the inactive hard drive, the following command in Terminal (CTRL+ALT+T) can remove it from the RAID1 group:

   sudo mdadm --zero-superblock /dev/sdX

    

4. If it boots fine, add the hard drive back and the let the Operating System resync the RAID content.

5. To resynch the content from the active hard drive and recover the group, you can run the following command in Terminal (CTRL+ALT+T):

   sudo mdadm --manage /dev/md0 --ass /dev/sdX

    

6. To check the RAID status run this Terminal command (CTRL+ALT+T):

   cat /proc/mdstat

    

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Option for Extended Display missing in RAID installed Ubuntu

Some people using 12.04 can only see clone mode.

This issue can be resolved by moving from integral graphics to an add-on PCI graphics card or by updating to Ubuntu LTS Version 14.04 or 16.04.

Here are some articles that go into Ubuntu Video in greater detail:

• Upgrading Ubuntu to the latest version?
• Video on Dell PCs with Ubuntu installed
• Configure multiple displays on a Dell PC with Ubuntu installed

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Additional Info:

Note:
Software support for Canonical is through the following methods:

• Ubuntu Community Support - Ask Ubuntu 
• Ubuntu Community Forums 
• Search for Frequently Asked Questions (FAQs) on Ubuntu

Technical Support is provided by Dell:

• Contact Us

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