Installation guide

Chapter 13. Redundant Array of Independent Disks (RAID)
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As mentioned earlier in Section 13.5, “ Linux RAID Subsystems”, the dmraid tool cannot configure
RAID sets after creation. For more information about using dmraid, refer to man dmraid.
13.8. Advanced RAID Device Creation
In some cases, you may wish to install the operating system on an array that can't be created after
the installation completes. Usually, this means setting up the /boot or root file system arrays on a
complex RAID device; in such cases, you may need to use array options that are not supported by
Anaconda. To work around this, perform the following procedure:
1. Insert the install disk as you normally would.
2. During the initial boot up, select Rescue Mode instead of Install or Upgrade. When the system
fully boots into Rescue mode, the user will be presented with a command line terminal.
3. From this terminal, use parted to create RAID partitions on the target hard drives. Then, use
mdadm to manually create raid arrays from those partitions using any and all settings and options
available. For more information on how to do these, refer to Chapter 4, Partitions, man parted,
and man mdadm.
4. Once the arrays are created, you can optionally create file systems on the arrays as well. Refer to
Section 2.2, “Overview of Supported File Systems” for basic technical information on file systems
supported by Red Hat Enterprise Linux 6.
5. Reboot the computer and this time select Install or Upgrade to install as normal. As Anaconda
searches the disks in the system, it will find the pre-existing RAID devices.
6. When asked about how to use the disks in the system, select Custom Layout and click Next. In
the device listing, the pre-existing MD RAID devices will be listed.
7. Select a RAID device, click Edit and configure its mount point and (optionally) the type of file
system it should use (if you didn't create one earlier) then click Done. Anaconda will perform the
install to this pre-existing RAID device, preserving the custom options you selected when you
created it in Rescue Mode.
Note
The limited Rescue Mode of the installer does not include man pages. Both the man mdadm
and man md contain useful information for creating custom RAID arrays, and may be needed
throughout the workaround. As such, it can be helpful to either have access to a machine with
these man pages present, or to print them out prior to booting into Rescue Mode and creating
your custom arrays.