Category:Software RAID - Revision history

Ledhed at 16:35, 22 October 2007

2007-10-22T16:35:15Z

Ledhed: /* Creating the Array with MDADM */

2007-02-26T23:47:29Z

‎Creating the Array with MDADM

Ledhed: /* Creating the Array with MDADM */

2007-02-26T23:46:16Z

‎Creating the Array with MDADM

Ledhed: /* Creating the Array with MDADM */

2007-02-26T23:41:19Z

‎Creating the Array with MDADM

Ledhed: /* Partitioning */

2007-02-26T23:40:57Z

‎Partitioning

Ledhed: /* Booting from RAID Partition */

2007-02-26T23:40:12Z

‎Booting from RAID Partition

Ledhed at 23:38, 26 February 2007

2007-02-26T23:38:40Z

Ledhed at 23:35, 26 February 2007

2007-02-26T23:35:46Z

Ledhed at 23:35, 26 February 2007

2007-02-26T23:35:25Z

New page

'''Linux Software RAID'''
MDADM is a set of utilities to manage software RAID Arrays in Linux
Reference: http://www.linuxcommand.org/man_pages/mdadm8.html

Note: Most modern Distro's provide a way to create a RAID volume durring the install process. In my experience, Fedora fails to install the boot loader to both driver (assuming you are booting from an Array), and Ununtu fails to install the boot loader to either drive, this requires you to boot from the Ubuntu install CD, and choose the "boot from first harddisk" option.

== Partitioning ==

To create a software RAID volume you must create a minimum of two partition of the same size (preferably on seperate physical disks)

Creating the partitions with fdisk
Reference: http://www.linuxcommand.org/man_pages/fdisk8.html
fdisk /dev/sda
This will partition the first physical SCSI drive

Command reference:
p = Print/View Drive partition information
d = Delete Partition
n = New partition
t = Partition Type (FAT16, FAT32, Linux, etc...)
w = Write changes to partition table
q = quit

After creating the partitions you need to change their type:
type = 82 (Linux RAID Autodetect)

Finish up by pressing 'w'

Now repeat the above process
fdisk /dev/sdb

Make sure to create a partition of EXACTLY the same size and type.

== Creating the Array with MDADM==

== Formatting the Array ==
Choosing a filesystem goes way beyond the scope of this page, but here are a few examples:

mkfs.ext3 /dev/md0
or
mkfs.reiserfs /dev/md1

Follow the same procedure for any of the many Filesystems supported by Linux.

== Booting from RAID Partition ==
To boot from a RAID partition is much like booting from a single partition, you must install a boot loader. When creating a RAID 0 (Mirror) you will want to install grub (or lilo) to the boot sector of both drives. By doing this if 1 drive fails and you must reboot. The boot loader is available on either drive. Note: you may need to make changes to your BIOS to adjust for boot order.

Reference: http://www.linuxcommand.org/man_pages/grub8.html

grub
>root (hd0,0)
>setup (hd0)

>root (hd1,0)
>setup (hd1)
>quit

You now need to make changes to your grub.conf (or menu.list depending on distro)
You should find a few lines that look something like this:

Copy that line and change the title and drive numbers to match your second drive, it should look something like this:

Now if either drive fails, you can choose the Mirrored drive from the boot menu.

@@ Line 34: / Line 34: @@
 Reference: http://www.linuxcommand.org/man_pages/mdadm8.html
   mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
-Repeat this for each set of corresponding partitions you've created, moifying /dev/mdx and /dev/sdx
+Repeat this for each set of corresponding partitions you've created, moifying /dev/mdx and /dev/sdx to correlate with the array number and partition number.
 == Formatting the Array ==

← Older revision		Revision as of 23:35, 26 February 2007
Line 66:		Line 66:

	Now if either drive fails, you can choose the Mirrored drive from the boot menu.		Now if either drive fails, you can choose the Mirrored drive from the boot menu.
		+
		+
		+	[[Category:Linux]]

@@ Line 60: / Line 60: @@
 You now need to make changes to your grub.conf (or menu.list depending on distro)
 You should find a few lines that look something like this:
-Copy that line and change the title and drive numbers to match your second drive, it should look something like this:
+Copy and change the title and drive numbers to match your second drive, it should look something like this:
 Now if either drive fails, you can choose the Mirrored drive from the boot menu.

@@ Line 31: / Line 31: @@
 == Creating the Array with MDADM==
-MDADM is a set of utilities to manage software RAID Arrays in Linux
+MDADM is a set of utilities to manage software RAID Arrays in Linux.<br>
 Reference: http://www.linuxcommand.org/man_pages/mdadm8.html
 == Formatting the Array ==

@@ Line 7: / Line 7: @@
-Creating the partitions with fdisk
+Creating the partitions with fdisk<br>
 Reference: http://www.linuxcommand.org/man_pages/fdisk8.html
   fdisk /dev/sda
@@ Line 29: / Line 29: @@
 Make sure to create a partition of EXACTLY the same size and type.
 == Creating the Array with MDADM==

@@ Line 45: / Line 45: @@
 Follow the same procedure for any of the many Filesystems supported by Linux.
-== Booting from RAID Partition ==
+== Booting from RAID Partitions ==
 To boot from a RAID partition is much like booting from a single partition, you must install a boot loader.  When creating a RAID 0 (Mirror) you will want to install grub (or lilo) to the boot sector of both drives. By doing this if 1 drive fails and you must reboot.  The boot loader is available on either drive. Note:  you may need to make changes to your BIOS to adjust for boot order.

@@ Line 1: / Line 1: @@
 '''Linux Software RAID'''
-MDADM is a set of utilities to manage software RAID Arrays in Linux
+Most modern Distro's provide a way to create a RAID volume durring the install process. In my experience, Fedora fails to install the boot loader to both driver (assuming you are booting from an  Array), and Ununtu fails to install the boot loader to either drive, this requires you to boot from the Ubuntu install CD, and choose the "boot from first harddisk" option.
-Reference: http://www.linuxcommand.org/man_pages/mdadm8.html
-−
-Note: Most modern Distro's provide a way to create a RAID volume durring the install process. In my experience, Fedora fails to install the boot loader to both driver (assuming you are booting from an  Array), and Ununtu fails to install the boot loader to either drive, this requires you to boot from the Ubuntu install CD, and choose the "boot from first harddisk" option.
 == Partitioning ==
@@ Line 35: / Line 32: @@
 == Creating the Array with MDADM==
+MDADM is a set of utilities to manage software RAID Arrays in Linux