Storage configuration for hosts that run the Linux operating system

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If you are completing storage configuration for Linux® host systems, each of the LUNs for the attached storage system has a special device file in the Linux directory /dev.

Hosts that use Linux 2.4 kernel operating systems have a maximum of 128 disks that are based on the major numbers that are available. The entries for all 128 devices are added by the operating system automatically.

Linux hosts can have as many disks as the system allows. The following website provides the current information about configuration maximums:

www.ibm.com/support

The range of devices for each type of kernel follows.

Device range without a Device Mapper Multipathing
/dev/sda to /dev/sddx
Device range with an Device Mapper Multipathing
  • Linux 2.4 kernel operating systems have the following range:
    • /dev/vpatha, vpathb...vpathp
    • /dev/vpathaa, vpathab...vpathap
    • /dev/vpathba, vpathbb...vpathbp...
    • /dev/vpathza, vpathzb...vpathzp
    • /dev/vpathaaa, vpathaab...vpathaap...
  • Linux 2.6 kernel operating systems have the following range:
    • /dev/vpatha, vpathb...vpathz
    • /dev/vpathaa, vpathab...vpathaz
    • /dev/vpathba, vpathbb...vpathbz...
    • /dev/vpathza, vpathzb...vpathzz
    • /dev/vpathaaa, vpathaab...vpathaaz...
Figure 1. Example of range of devices for a host that is running the Linux operating system when not using the Device Mapper Multipathing
# ls –l /dev/sda
brw-rw---- 1 root disk 8, 0 Aug 24 2005 /dev/sda
Figure 2. Example of range of devices for a host that is running the Linux operating system when using the Device Mapper Multipathing
# ls –l /dev/vpatha
brw-rw---- 1 root disk 8, 0 Aug 24 2005 /dev/vpatha