IBM DS8800 Introduction And Planning Manual page 202

IBM i LUN serial suffix number
Use this control switch setting only when you attach more than one DS8000 series
model to an AS/400 or IBM i host and the last three digits of the worldwide node
name (WWNN) are the same on any of the DS8000 units.
Control switch settings - attachment to IBM System z
The following control switch settings are specific to System z.
Control-unit initiated reconfiguration (CUIR) support
Present SIM data to all hosts
Control unit threshold
Device threshold
Media threshold
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Introduction and Planning Guide
Control-unit initiated reconfiguration (CUIR) allows automation of channel
path quiesce and resume actions during certain service actions. This setting
eliminates the requirement for manual actions from the host.
Service Information Messages (SIMs) are offloaded to the first I/O request
directed to each logical subsystem in the storage facility if the request is
device or control unit related, or offloaded to the individual logical volume
when the request is media related. This control switch determines whether
SIMs are sent to all, or to only the first, attached IBM System z LPAR
making an I/O request to the logical system or logical volume.
This control switch provides the threshold level, presenting a SIM to the
operator console for controller related errors. SIMs are always sent to the
attached IBM System z hosts for logging to the Error Recording Data Set
(ERDS). SIMs can be selectively reported to the IBM System z host
operator console, as determined by SIM type and SIM severity.
This control switch provides the threshold level, presenting a SIM to the
operator console for device related errors. Device threshold levels are the
same type and severity as control unit threshold settings.
This control switch provides the threshold level, presenting a SIM to the
operator console for media related errors. Media threshold levels are the
same type and severity as control unit threshold settings.