Appendix A: Using Device File Types
Prior to the HP-UX 11i v3 release, there were only legacy device special files. Starting with the HP-UX
11i v3 release, mass storage devices, such as disk devices and tape devices, have two types of
device files, persistent device special files and legacy device special files. You can use both to access
the mass storage device independently, and can co-exist on the same system.
A legacy device special file is locked to a particular physical hardware path, and does not support
agile addressing. This device special file contains hardware path information such as SCSI bus,
target, and LUN (Logical Unit Number) in the device file name and minor number. Specifically, the
class and instance portions of the device special file name indicate hardware path information and
are in the format c#t#d# as follows:
The instance number assigned by the operating system to the interface card. It is a
decimal number with a range of 0 to 255. There is no direct correlation between instance
number and physical slot number.
The target address on a remote bus (for example, SCSI address). It is a decimal number
with a typical range of 0 to 15.
The device unit number at the target address (for example, the LUN in a SCSI device). It
is a decimal number with a typical range of 0 to 7.
A persistent device special file is associated with a LUN hardware path, transparently supporting
agile addressing and multipathing. In other words, a persistent device special file is unchanged if the
LUN is moved from one HBA to another, moved from one switch or hub port to another, presented via
a different target port to the host, or configured with multiple hardware paths. Like the LUN hardware
path, the binding of device special file to device persists across reboots, but is not guaranteed to
persist across installations.
Persistent and Legacy device special files are represented as follows:
Persistent device special files, (/dev/disk/disk3), or
Legacy device special file names, (/dev/dsk/c0t6d6)
To display the mapping between the legacy and persistent device special files, use the ioscan
command. Either a legacy or persistent special file can be specified as an argument. Multiple legacy
special files mapping to the persistent special file are separated by a white space, as follows:
# ioscan -m dsf /dev/disk/disk240
Persistent DSF Legacy DSF(s)
========================================
/dev/disk/disk240 /dev/dsk/c17t1d2
/dev/dsk/c19t1d2
# ioscan -m dsf /dev/dsk/c17t1d2
Persistent DSF Legacy DSF(s)
========================================
/dev/disk/disk240 /dev/dsk/c17t1d2
# ioscan -m dsf /dev/dsk/c19t1d2
Persistent DSF Legacy DSF(s)
========================================
/dev/disk/disk240 /dev/dsk/c19t1d2
You can derive hardware path information, class names, and instance numbers from ioscan output;
see ioscan(1M) for more information. There are three different types of paths to a device: legacy
hardware path, lunpath hardware path, and LUN hardware path. For more information, see intro(7).
(198 strony)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Komentarze do niniejszej Instrukcji