Technical data

180 Fabric OS Encryption Administrator’s Guide (DPM)
53-1002720-02
SRDF LUNs
3
1. Log in to the switch that hosts the LUN as Admin or FabricAdmin.
2. Enter the cryptocfg
--enable -LUN command followed by the CryptoTarget container name,
the LUN Number, and the initiator PWWN.
FabricAdmin:switch> cryptocfg --enable -LUN my_disk_tgt 0x0 \
10:00:00:00:c9:2b:c9:3a
Operation Succeeded
SRDF LUNs
The Symmetrix Remote Data Facility (SRDF) transmits data that is being written to a local
Symmetrix array to a remote symmetrix array. The replicated data facilitates a fast switch-over to
the remote site for data recovery.
SRDF supports the following methods of data replication:
• Synchronous Replication provides real-time mirroring of data between the source Symmetrix
and the target Symmetrix systems. Data is written simultaneously to the cache of both systems
in real time before the application I/O is completed, thus ensuring the highest possible data
availability.
• Semi-Synchronous Replication writes data to the source system, completes the I/O, and then
synchronizes the data with the target system. Since the I/O is completed prior to synchronizing
data with the target system, this method provides an added performance advantage. A second
write will not be accepted on a Symmetrix source device until its target device has been
synchronized.
• Adaptive Copy Replication transfers data from the source devices to the remote devices
without waiting for an acknowledgment. This is especially useful when transferring large
amounts of data during data center migrations, consolidations, and in data mobility
environments.
• Asynchronous Replication places host writes into chunks and then transfers an entire chunk to
the target system. When a complete chunk is received on the target system, the copy cycle is
committed. If the SRDF links are lost during data transfer, any partial chunk is discarded,
preserving consistency on the target system. This method provides a consistent point-in-time
remote image that is not far behind the source system and results in minimal data loss if there
is a disaster at the source site.
SRDF pairs
Remote replication is implemented by establishing a synchronized pair of SRDF devices connected
by FC or IP links. A local source device is paired with a remote target device while data replication is
occurring. While the SRDF devices are paired, the remote target device is not locally accessible for
read or write operations. When the data replication operation is completed, the pair may be split to
enable normal read/write access to both devices. The pair may be restored to restore the data on
the local source device.
Figure 92 shows the placement of Brocade Encryption Switches in an SRDF configuration. When
encryption is enabled for the R1 LUN, encrypted data written by the local application server to the
R1 LUN is replicated on the R2 LUN. The data is encrypted using a DEK that was generated on the
local encryption switch and stored on the local key vault. When each site has an independent key