Installing Software Raid (MDAMD) on the Appliance

From IHRIS Wiki
(Redirected from MDAMD Appliance)
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Create a Bootable USB Drive

First, you will need to download 

open.intrahealth.org/livecd.iso

and burn it to a USB stick: 

[Ubuntu Start Menu]
[System]
[Administration]
[Startup Disk Creator]

Booting

No2 boot the appliance with the USB Disk inserted. Note, you may have to go into the BIOS and select that the USB boots before the hard drives, or press [F10] right a system startup to get the boot menu.

At the beginning of the boot is the boot menu ( GRUB boot loader) where you need to do: 

[F6] (Other Options)
Select to Disable dmraid
[Esc]
Choose to install Ubuntu/iHRIS

Setting Up Partitions

Continue as usual until the partition disks screen 

[Ctrl]-[Alt]-[F1]  will take you to a prompt

Here you do 

sudo apt-get install mdadm

You will need to create partitions via fdisk. If iHRIS has been installed on the appliance before, partitions may already exist. In this case we will need to remove them first 

sudo fdisk /dev/sda
 #(Optional: Removing existing partitions)
   p (print the partition table -- you should see something like the following but with different numbers)
        Device Boot      Start         End      Blocks   Id  System
       /dev/sda1   *           1       18662   149902483+  83  Linux
       /dev/sda2           18663       19457     6385837+   5  Extended
       /dev/sda5           18663       19457     6385806   82  Linux swap / Solaris
      (we want now to remove each of these partitions, 1 2 and 5)
   d (delete partition)
   1 (select partition 1 to delete)
   d (delete partition)
   2 (select partition 1 to delete)
   d (delete partition)
   5 (select partition 1 to delete)
   
 #Creating new partitions
   n  (new partition)
   p  (primary)
   1 (partition 1)
   1 (first cylinder)
   9242 (last cylinder)
   a (toggle boot partition flag)
   1  (select the first partition to be bootable)
   n  (new partition) 
   p  (extended)
   2 (partition 2)
   9243 (first cylinder)
   9729 (last cylinder)
   n    (new parition)
   l    (logical partition)
   9243 (first cylinder)
   9729 (last cylinder)
   t (set partition type)
   5 (parition 5)
   82 (swap)
   p (print to make sure everything matches below)
   w  (write and exit)

Now we need to repeat the creation of partitions for the second hard disk ( /dev/sdb ). There shouldn't be any existing partitions here so we won't need to delete them first. 

sudo fdisk /dev/sdb
 #Creating new partitions
   n  (new partition)
   p  (primary)
   1 (partition 1)
   1 (first cylinder)
   9242 (last cylinder)
   a (toggle boot partition flag)
   1  (select the first partition to be bootable)
   n  (new partition) 
   p  (extended)
   2 (partition 2)
   9243 (first cylinder)
   9729 (last cylinder)
   n    (new parition)
   l    (logical partition)
   9243 (first cylinder)
   9729 (last cylinder)
   t (set partition type)
   5 (parition 5)
   82 (swap)
   p (print to make sure everything matches below)
   w  (write and exit)
..blah blah..

and the partitions should be identical: 

/dev/sda1 start 1 end 9242 id 83 (linux)
/dev/sda2 start 9243 end 9728 id 5 (extended)
/dev/sda5 start 9243 end 9728 id 82 (swap)
/dev/sdb1 start 1 end 9242 id 83 (linux)
/dev/sdb2 start 9243 end 9728 id 5 (extended)
/dev/sdb5 start 9243 end 9728 id 82 (swap)

Assembling the Raid Array

Now assemble the software raid array 

sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
sudo mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda5 /dev/sdb5

on success it should say "mdadm: array /dev/md0 started"

Selecting to Install on the RAID array

To return to installed: 

[Alt]-[F7]

From the partition manager thing, click "Back" and then "Forward" so that is will rescan the disks 

Select 'Specify the partitions manually'
Click "Forward"
Right click on /dev/md0 and create a new partition table
Under /dev/md0 you should see "free space".  Right click and use as "ext3" with mount point "/"
Right click on /dev/md1 and create a new partition table
Under /dev/md1 you should see "free space".  Right click and use as swap
Click "Forward"

Boot Loader Options

When you get to the "Ready to Install" Screen select: 

[Advanced]
Make sure install boot loader is checked
Choose '/dev/md0' under "Device for bot loader installation"

Installing the Boot loader on the Raid Array

Just before the installation is finished, it tries to install grub, the boot loader, onto the /dev/md0 our raid disk. It may fail by saying: 

executing grub-install /dev/md0 failed.  This is a fatal error.

There is a bug report. Luckily there is a workaround: 

[Ctrl]-[Alt]-[F1]
sudo parted /dev/sda set <partition_number> bios_grub on
grub-install --modules=raid --no-floppy /dev/sda
[Alt]-[F7]


Known Issue for Karmic

http://www.ubuntu.com/testing/karmic/beta?info=EXLINK with possible workaround http://www.brandonchecketts.com/archives/booting-from-a-software-raid-device-on-ubunto-karmic-910

Automatic boot on failure

Optionally, and not recommended, you can have the Appliance continue to boot if one of the hard drive failse by editting this file /etc/initramfs-tools/conf.d/mdadm change "BOOT_DEGRADED=false" to "BOOT_DEGRADED=true"

The reason that this is recommended is that we will have no way of knowing that one of the hard drives failed and then the second one may fail.

LCD Menu

sudo usblcd spash /home/lcdmenu/bin/splash.txt


After rebooting, maybe modify /etc/fstab and set 

 /dev/md0 to "relatime" instead of defaults

Background

https://help.ubuntu.com/community/Installation/SoftwareRAID#Formatting

Retrieved from "https://wiki.ihris.org/mediawiki/index.php?title=Installing_Software_Raid_(MDAMD)_on_the_Appliance&oldid=53327"