Adaptive copy d disk mode w wp mode acp off mirror

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A(daptive Copy) : D = Disk Mode, W = WP Mode, . = ACp off (Mirror) T(ype) : 1 = R1, 2 = R2 (Consistency) E(xempt): X = Enabled, . = Disabled, M = Mixed, - = N/A SRDF/Asynchronous Operations
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8 Copyright 2015 EMC Corporation. All rights reserved. SRDF/A can be enabled when the device pairs are operating in any of the listed modes. In the case of Adaptive Copy Disk to SRDF/A transition, it takes two additional cycle switches after resynchronization of data for the R2 devices to be consistent. SRDF/Asynchronous Operations
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9 Copyright 2015 EMC Corporation. All rights reserved. Any SRDF/A operation (with the exception of consistency exempt, discussed later in the module) must be performed on ALL devices in an SRDF group (RA group). This means that all devices in an SRDF group must be in the same SRDF Device group as well. This is in contrast with SRDF/S, where operations can be performed on a subset of devices in an SRDF group. SRDF/Asynchronous Operations
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10 Copyright 2015 EMC Corporation. All rights reserved. The mode of SRDF operation is set to Asynchronous for the device pairs in the device group asyncdg1 . SRDF/A consistency is enabled. symrdf query rdfa gives detailed information about the SRDF/A state of the device group. As described earlier transition from Synchronous to Asynchronous mode is immediate. The consistency state of the R2 devices is displayed in the query: True. The RDF pair state reflects Consistent. SRDF/Asynchronous Operations
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11 Copyright 2015 EMC Corporation. All rights reserved. In this example, the device pairs are in SRDF Adaptive Copy Disk Mode ( C.D. ). There are R2 invalid tracks. SRDF/Asynchronous Operations
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12 Copyright 2015 EMC Corporation. All rights reserved. The transition into SRDF/A is immediate ( A..X. ), and the group has been enabled for consistency. However, the pair state is SyncInProg . R2 device does not have consistent data until the pair state is synchronized and then at least two cycle switches have completed. Consistency of the R2 data is also displayed by the highlighted field in the output: “R2 Data is Consistent”. As can be seen it is “False” currently. Legend for MODE: M (ode of Operation) : A = Async , S = Sync, E = Semi-sync, C = Adaptive Copy : M = Mixed A(daptive Copy) : D = Disk Mode, W = WP Mode, . = ACp off C (onsistency State) : X = Enabled , . = Disabled, M = Mixed, - = N/A (Consistency) E(xempt): X = Enabled, . = Disabled, M = Mixed, - = N/A SRDF/Asynchronous Operations
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13 Copyright 2015 EMC Corporation. All rights reserved. With consistency exempt, the existing devices in an active SRDF/A session need not be suspended when adding new devices to the session. Consistency is maintained for the existing devices. The new devices are excluded from the consistency calculation until they are synchronized, move into a consistent state, and the consistency exempt attribute has been removed. Enginuity automatically clears the consistency exempt status. There is no CLI to do this. It is critical to wait for the new devices to go into a Consistent RDF Pair state, before using the R1 device for application data. As long as the Consistency Exempt
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