No, it cannot be run concurrently. It requires a dedicated system.
From the help:
If option *SYSBAS is specified on the ASPDEV parameter, all
subsystems must be inactive before the RCLSTG command can be
specified. The End System (ENDSYS) or End Subsystem (ENDSBS)
command with *ALL specified on the SBS parameter can be used
to make the subsystems inactive. You must have job control
(*JOBCTL) authority to use the ENDSYS or the ENDSBS command.
If option *SYSBAS is specified for the ASPDEV parameter, this
job must be in the controlling subsystem and must be the only
job active in the system.
Network server descriptions (NWSD) must be varied-off in order
to run RCLSTG.
Note: The RCLSTG command can be a long-running function,
depending on the number and type of objects in the system, and
the amount of damage to them. Because RCLSTG touches each
object multiple times, having enough memory can significantly
reduce the time required to run RCLSTG. Conversely, having too
little memory can lead to storage thrashing which can
significantly increase the time required to run RCLSTG.
Rob Berendt
midrange.com
