Purpose
Changes
the characteristics of a device.
Syntax
chdev -dev Name [ -perm ] [ -attr Attribute=Value
[ Attribute=Value... ] ]
Description
The chdev command
changes the characteristics of the device specified with the given
device logical name (the -dev Name flag). Some changes
may not be allowed when the device is in the Available state.
When
the -perm flag is not specified, the chdev command applies
the changes to the device and updates the database to reflect the
changes. If the -perm flag is specified, only the database
is updated to reflect the changes, and the device itself is left unchanged.
This is useful in cases where a device cannot be changed because it
is in use; in which case, the changes can be made to the database
with the -perm flag, and the changes will be applied to the
device when the system is restarted. Not all devices support the -perm flag.
Attention: To protect the Configuration database, the chdev command
is not interruptible. To stop this command before execution is complete
could result in a corrupted database.
Flags
| -attr Attribute=Value |
Specifies the device attribute value pairs used
for changing specific attribute values. The Attribute=Value parameter
can use one attribute value pair or multiple attribute value pairs
for one -attr flag. If you use an -attr flag with multiple
attribute value pairs, the list of pairs must be separated by spaces.
For example, entering -attr Attribute=Value lists one
attribute value pair per flag, while entering -attr Attribute1=Value1
Attribute2=Value2 lists more than one attribute value pair. |
| -dev Name |
Specifies the device logical name, indicated
by the Name parameter, whose characteristics are to be changed. |
| -perm |
Changes the device's characteristics permanently
without actually changing the device. This is useful for devices that
cannot be made unavailable and cannot be changed while in the available
state. By restarting the system, the changes will be applied to the
device. Not all devices support the -perm flag. |
Examples
- To change the retention instructions of the 4mm SCSI tape drive rmt0 so
that the drive does not move the tape to the beginning, then to the
end, and then back to the beginning each time a tape is inserted or
the drive is powered on, type:
chdev -dev rmt0 -attr ret=no
- To change the SCSI ID of the available SCSI adapter scsi0 that
cannot be made unavailable or changed due to available disk drives
connected to it, type:
chdev -dev scsi0 -attr id=6 -perm
To
apply the change to the adapter, shutdown and restart the system.
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