SET RDEVICE DASD
Authorization
Privilege Class: B
Purpose
You can enter SET RDEVICE commands for the following DASD types: 3380, 3390 and 9336.
These DASD types respond to the sense ID request instruction. You only need to enter SET RDEVICE
commands for them if you want to specify one of the following operands:
- SHARED YES
- MDC DFLTOFF
- MDC OFF
- NOTSENSED.
Operands
- rdev
- rdev1-rdev2
- specifies one or more real device numbers to be defined or changed. A real DASD in the active configuration can be entered as a 4-digit hexadecimal device number between X'0000' and X'FFFF'. For a real DASD in the active or standby configuration, the device can be a 5-digit hexadecimal number between X'00000' and X'3FFFF' with the leading digit specifying the subchannel set where the device is defined. A range of devices cannot span subchannel sets. The maximum number of devices allowed within a range is 256.
- EQid eqid
- assigns the device equivalency ID (EQID) eqid to the RDEV. The eqid is a string of 1–8 alphanumeric characters. Note that for this device class, the specified EQID must be unique across all devices on the system.
- NOEQid
- removes a previously assigned EQID from this RDEV and reverts back to a system-generated EQID. If no EQID was previously assigned by a user, no action takes place.
- TYpe DASD
- tells CP the specified device or devices are DASDs.
- SHAREd
- tells CP to share
the devices concurrently among multiple real systems.
In an SSI cluster, this setting specifies whether the devices are to be shared outside the SSI cluster.
- NO
- tells CP not to share the devices among multiple real systems. The default is NO.
- YES
- tells CP to share the devices among multiple real systems.
- MDC
- tells CP
whether you want the device or devices to be cached in the minidisk cache.
- DFLTON
- (the default if the SHARED option is not specified or the SHARED NO option is specified.) Tells CP to cache data on the real device in the minidisk cache except for minidisks for whom caching is specifically disabled via the MINIOPT NOMDC directory statement or the SET MDCACHE MDISK OFF command.
- OFF
- (the default if the SHARED YES option is specified.) Tells CP to not cache data on the real device in the minidisk cache.
- DFLTOFF
- tells CP to not cache data on the real device in the minidisk cache except for minidisks for whom caching is specifically enabled via the MINIOPT MDC directory statement or the SET MDCACHE MDISK ON command.
- SENSed
- tells CP to use the information returned from a sense ID request to determine the characteristics of this DASD. If omitted, the default is SENSED.
- NOTSENSed
- tells CP not to use the information returned from a sense ID request to determine the characteristics of this DASD.
Usage Notes
- Not all DASD types are eligible for caching in the minidisk cache. If you specify MDC DFLTON or MDC DFLTOFF for a device that is not cache eligible, data on that device will not be cached.
- When setting an EQID for a device of this class, the specified EQID must be unique across all devices in the system. If the specified EQID already exists, you will receive message HCP048E and the RDEV will not be created.
- The system cannot generate EQIDs for devices that do not support RCD CCW.
- Specifying a 5-digit hexadecimal device number when defining an RDEV might place in into the active configuration. This would occur if there is not already a matching device number that is in the active configuration.
Examples
Example 1:
To specify a shared DASD with minidisk caching off at device number 0410, enter the following SET
RDEVICE command:
set rdevice 0410 type dasd shared yes
Example 2:
To define a non-shared DASD at device number 500 with minidisk caching enabled on a device only
for those minidisks that have specifically enabled caching, use the following SET RDEVICE command:
set rdevice 500 type dasd mdc dfltoff
Example 3:
To specify a shared DASD with minidisk caching off at device number 0252 with an EQID of
ABCDEFGH, enter this SET RDEVICE command:
set rdevice 0252 eqid ABCDEFGH type dasd shared yes
Example 4:
To specify a shared DASD with minidisk caching off at device number 0252 and remove any
previously defined EQID, enter this SET RDEVICE command:
set rdevice 0252 noeqid type dasd shared yes
Responses
After CP has issued a message for each device address affected by a SET RDEVICE command, the
following summary response is displayed:
xxx RDEV(s) specified; yyy RDEV(s) changed; zzz RDEV(s) created
Messages
- HCP002E Invalid operand - operand
- HCP003E Invalid option - command contains extra option(s) starting with option
- HCP048E EQID must be unique for the specified device class.
- HCP048E Specified EQID already assigned to a different device.
- HCP6000E The range of device numbers cannot exceed 256.
- HCP6704E Missing token at end of line
- HCP6706E Invalid address range - range