Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

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SRDF/Metro Smart DR pair states

Device pairs that are subject to any SRDF/Metro Smart DR operation need to be in the correct state. Otherwise, the operation fails.

The Solutions Enabler SRDF Family State Tables Guide lists control actions and the prerequisite pair state for each action.

Monitor SRDF/Metro Smart DR describes the SYMCLI commands to verify pair states.

The following tables list the name and description of both the SRDF/Metro and the DR pair states in an SRDF/Metro Smart DR environment.

SRDF/Metro pair states

Table 1. SRDF/Metro pair states
Pair state	Description
ActiveActive	The R1 and the R2 are in the default SRDF/Metro configuration which uses a Witness: There are no invalid tracks between the two pairs. The R1 and the R2 are Ready (RW) to the hosts.
ActiveBias	The R1 and the R2 are in the default SRDF/Metro configuration which uses a witness, however, the witness is in a failed state and not available. There are no invalid tracks between the two pairs. The R1 and the R2 are Ready (RW) to the hosts.
SyncInProg	Synchronization is currently in progress between the R1 and the R2 devices. There are existing invalid tracks between the two pairs, and the logical links between both sides of an SRDF pair are up.
Suspended	The SRDF links have been suspended and are not ready or write disabled. If the R1 is ready while the links are suspended, any I/O accumulates as invalid tracks owed to the R2.
Partitioned	The SRDF group between the two SRDF/Metro arrays is offline. If the R1 is ready while the group is offline, any I/O accumulates as invalid tracks owed to the R2.
Unknown	If the environment is not valid, the SRDF/Metro session state is marked as Unknown. If the SRDF/Metro session is queried from the DR array and the DR Link State is Offline, the SRDF/Metro session state is reported as Unknown.
Invalid	This is the default state when no other SRDF state applies. The combination of the R1 device, the R2 device, and the SRDF link states do not match any other pair state, or there is a problem at the disk director level.

DR pair states

Table 2. DR pair states
Pair state	Description
Synchronized	NOTE:This state is only applicable when the DR pair is in Acp_disk mode. The background copy between the SRDF/Metro and DR is complete and they are synchronized. The MetroR2 device states are dependent on the SRDF/Metro session state. The DR side is not host accessible with the devices in a Write Disabled SRDF state. The MetroR2 device states are dependent on the SRDF/Metro session state.
Consistent	NOTE:This state is only applicable when the DR pair is in Async mode. This is the normal state of operation for device pairs operating in asynchronous mode indicating that there is a dependent-write consistent copy of data on the DR site. The MetroR2 device states are dependent on the SRDF/Metro session state.
TransIdle	NOTE:This state is only applicable when the DR pair is in Async mode. The SRDF/A session is active but it cannot send data in the transmit cycle over the SRDF link because the SRDF link is offline. There may be a dependent-write consistent copy of data on the DR devices. The background copy may not be complete. The MetroR2 device states are dependent on the SRDF/Metro session state.
SyncInProg	Synchronization is currently in progress between the SRDF/Metro and the DR devices. In Adaptive copy mode, the copy direction could be SRDF/Metro –> DR or SRDF/Metro <– DR In Async mode, the copy direction is SRDF/Metro –> DR The DR side is not accessible to the host. The MetroR2 device states are dependent on the SRDF/Metro session State
Suspended	Synchronization is currently suspended between the SRDF/Metro and the DR devices as the SRDF link is Not Ready and the DR side is not host accessible. Host writes accumulate and can be seen as invalids. The MetroR2 device states are dependent on the Metro session State
Split	MetroR1 and the DR side are currently ready to their hosts, but synchronization is currently suspended between the SRDF/Metro and the DR devices as the SRDF link is Not Ready. The MetroR2 device states are dependent on the Metro session State
Failed Over	Synchronization is currently suspended between the SRDF/Metro and the DR devices and the SRDF link is Not Ready. Host writes accumulate and can be seen as invalids If a failover command is issued when the DR Link state is not Offline: the SRDF/ Metro session is suspended MetroR1 and R2 are not host accessible If a failover command is issued when the DR state is Partitioned or TransIdle, and the DR Link state is Offline: the SRDF/Metro state does not change. the MetroR1 and MetroR2 device states regarding to their accessibility to the host do not change.
R1 Updated	The MetroR1 was updated from the DR side and both MetroR1 and MetroR2 are not host accessible. The SRDF/Metro session is suspended. There are no local invalid tracks on the R1 side, and the links are ready or write disabled.
R1 UpdInProg	The MetroR1 is being updated from the DR side and both MetroR1 and MetroR2 are not host accessible. The SRDF/Metro session is suspended. There are invalid local tracks on the source side, so data is being copied from the DR to the R1 device, and the links are ready.
Partitioned	If the DR mode is Async, the SRDF/A session is inactive. The SRDF group between MetroR1 and DR is offline. MetroR1, R2, and the DR side are either Ready or Write Disabled depending on whether or not they are accessible to the host.
Unknown	If the environment is not valid, the DR state is marked as Unknown. If queried from the MetroR2 array, and the MetroR2_Metro_RDFG and MetroR2_DR_RDFG are offline, the DR mode is Unknown.
Invalid	This is the default state when no other DR state applies. The combination of the MetroR1, MetroR2, and DR link states do not match any other pair state, or there is a problem at the disk director level.