Reducing and Increasing the Number of Usable Devices

As mentioned above, the maximum number of devices is defined through installation parameter MAXCONN. You can, however, limit the number of devices to be used (usable devices) through operator commands.

• To reduce the number of usable devices, issue operator command

  F IOASMON,STOP MEDIA=media‑name,DEVQTY=num|ALL

  where num is the number of logical devices to be brought down. num can be any integer from 1 through 99, or the value ALL can be specified instead.

  The STOP command determines which devices must be stopped, according to device status.

  • The specified number of INACTIVE devices are stopped.
  • If the number of devices to be stopped is greater than the number of devices that are presently INACTIVE, IDLE devices are stopped as well.
  • If the number of devices to be stopped is greater than the number of devices that are either INACTIVE or IDLE, BUSY/ACTIVE devices are stopped as well.

  Each BUSY device to be stopped completes the request it is processing before being assigned a status of INACTIVE.

• To increase the maximum number of devices, use operator command

  F IOASMON,START MEDIA=media‑name,DEVQTY=num|ALL

  where num is the number of logical devices to be brought up. num can be any integer from 1 through 100, or the value ALL can be specified instead.

  The maximum set by the START command cannot be greater than the number specified for Control‑V installation parameter MAXCONN.