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Communication failure—site 2 to quorum witness – HP 3PAR Operating System Software User Manual

Page 146

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Communication Failure—Site 1 to Quorum Witness and Site 1 to Site 2

In a dual-network communication failure between site 1 and the quorum witness, and between site
1 and site 2 (see

Figure 56 (page 146)

):

HP 3PAR StoreServ array B reacts to the isolation of HP 3PAR StoreServ array A just as it
would react to a failure of HP 3PAR StoreServ array A: HP 3PAR StoreServ array B performs
a failover to become the source site.

Conversely, HP 3PAR StoreServ array A cannot update the quorum witness due to the failure
of the non-remote-copy links. It “knows” that HP 3PAR StoreServ array B will fail over to become
the source site, so HP 3PAR StoreServ array A performs a failsafe operation to become the
target site.

A failover takes place; the host I/O goes to the new source volumes on HP 3PAR StoreServ
array B.

Replication of I/O across remote-copy links stops.

Figure 56 Communication Failure—Site 1 to Quorum Witness and Site 1 to Site 2

Communication Failure—Site 2 to Quorum Witness

In a communication failure between site 2 and the quorum witness (see

Figure 57 (page 147)

):

HP 3PAR StoreServ array B has lost connectivity with the quorum witness.

Remote-copy links are operational and the HP 3PAR StoreServ arrays are aware of each
other’s operational state.

A failover does not take place:

Host I/O continues to the source volumes.

Replication of I/O across RC links continues as usual.

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HP 3PAR Peer Persistence with Transparent Failover