Setting Up Disks for MapR
This section describes how to set up disks
during the normal installation process. Go to the disksetup
command page for information about other uses of this command.
MapR formats and uses disks for the Lockless
Storage Services layer (MapR File System), and records these disks
in the
disktab
file. In a production environment, or
when testing performance, MapR should be configured to use physical
hard drives and partitions. In some cases, it is necessary to reinstall the operating
system on a node so that the physical hard drives are available for direct use by MapR. Reinstalling the operating system
provides an unrestricted opportunity to configure the hard drives. If the installation
procedure assigns hard drives to be managed by the Linux Logical Volume Manager(LVM) by default, you should explicitly remove the
drives you plan to use with MapRMapR Data Platform from the LVM configuration. It is common to let
LVM manage one physical drive containing the operating system partition(s) and to leave
the rest unmanaged by LVM for use with MapRMapR Data Platform.NOTE It is not necessary to set up RAID
(Redundant Array of Independent Disks) on disks used by MapR File System. MapRMapR Data Platform uses the disksetup script to set up storage pools. In most cases, you should let
MapRMapR Data Platform
calculate storage pools using the default stripe width of two or three disks. If you
anticipate a high volume of random-access I/O, you can use the
-W
option with disksetup to specify larger storage
pools of up to 8 disks each.NOTICE For more information on setting up disks, see Drive
Configuration.
The following procedures are intended for use on physical clusters or Amazon EC2 instances. On
EC2 instances, EBS volumes can be used as MapRMapR Data Platform storage, although performance will be
slow.
NOTE If you are using MapR on Amazon EMR,
you do not have to use this procedure; the disks are set up for you
automatically.