3.7.0 HP StorageWorks HP Scalable NAS File Serving Software administration guide - HP Scalable NAS 3.7 for Linux (AG513-96002, October 2009)

Device names
The SCL uses unique device names to control access to shared SAN devices. These
names form the pathnames that servers use to access shared data.
When you import a SAN disk, the SCL gives it a global device name that represents
the entire disk. The name consists of psd followed by an integer. For example, psd1,
psd2, and psd25 are all valid names.
Individual disk partitions also have a global device name. It consists of the name
assigned to the disk followed by p and the partition number. For example, partition
6 on disk psd12 is represented as psd12p6.
Global device names are not dependent on the physical location of the disks. If you
move a disk that has already been assigned a global device name, it will keep that
name after the move.
If you import a disk that already has a device name, the SCL keeps that name if it is
not currently in use. If the name has been assigned to another device, the SCL assigns
a new name to the disk that you are importing.
Device database and membership partitions
The SCL stores the device name and physical UID for each imported disk in a device
database. When you configured HP Scalable NAS, you specified a set of SAN
partitions to be used for the database and for other functions related to SAN control.
These partitions are called membership partitions and are automatically imported
into the cluster. (For information about creating these partitions and fixing any
problems with them, see Manage membership partitions, page 358.)
HP Scalable NAS creates the device database on one of the membership partitions
and then replicates it to the other partitions. The database must be present for a
cluster to form. To ensure that the database is always available, it is recommended
that you create three membership partitions.
Device access
Once imported, a shared device can be accessed only with its global device name,
such as psd6p4. On each server, the SCL creates device node entries in the directory
/dev/psd for every partition on the disk. The names of the entries match the global
device names of the partitions. The original /dev entries for the partitions are
disabled, giving HP Scalable NAS complete control over all accesses to those shared
devices.
Configure the SAN86