Each of the attached
system LUNs 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:
https://datacentersupport.lenovo.com/
The range of devices for each type of kernel follows.
- Device range without a Subsystem Device Driver (SDD)
- /dev/sda to /dev/sddx
- Device range with an SDD
- 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 SDD# 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 SDD# ls –l /dev/vpatha
brw-rw---- 1 root disk 8, 0 Aug 24 2005 /dev/vpatha