devswmgr - utility to manage the device switch database
/sbin/devswmgr [-option [parameter]]
Displays the following information about the device switch database:
Whether a device switch database was read from the primary file or from
a backup file
The number of entries that are in the device switch table
-getnum [ driver=NAME ] [ instance=INSTANCENUM ]
Displays the major numbers that have been reserved by all drivers, a
named driver, or an instance of a named driver.
A driver that requires more than one entry in the device switch table
uses a unique instance number to reference each of its device switch
Displays help for the devswmgr command.
-release driver=NAME [ instance=INSTANCENUM ]
Releases all the major numbers for a device driver if just the driver
name is specified. Releases one major number for a device driver if
the NAME and the INSTANCENUM of the driver are specified.
The devswmgr command helps you manage the device switch table by displaying
information about the devices drivers in the table.
You can also use the command to release device switch table entries. Typi-
cally, you release the entries for a driver after you have unloaded the
driver and do not plan to reload it later. Releasing the entries frees
them for use by other device drivers.
1. The following example shows that a device switch table was loaded from
the primary device and that there are 70 entries in it:
% /sbin/devswmgr -display
Device switch information
device switch database read from primary file
device switch table has 70 entries
2. The following example shows the major numbers in the device switch
table that have been reserved for the driver named cam_disk:
% /sbin/devswmgr -getnum driver=cam_disk
Device switch reservation list
(*=entry in use)
driver name instance major
------------------------------- -------- -----
cam_disk 1 8*
The file that manages the device switch databases
The primary device switch database file
The backup device switch database file