EMC VMAX 100K, Руководство по эксплуатации продукта

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– One Capture
– One Transmit
n
On the R2 side:
– One Receive
– One Apply
Each cycle switch moves the delta set to the next cycle in the process.
A new capture cycle cannot start until the transmit cycle completes its commit of
data from the R1 side to the R2 side.
Cycle switching can occur as often as the preset Minimum Cycle Time, but it can
also take longer since it is dependent on both the time it takes to transfer the data
from the R1 transmit cycle to the R2 receive cycle and the time it takes to destage
the R2 apply cycle.
Cycle switching in asynchronous mode
The number of capture cycles supported at the R1 side varies depending on whether
one or both the arrays in the solution are running HYPERMAX OS.
HYPERMAX OS
SRDF/A SSC sessions where both arrays are running HYPERMAX OS have one or
more Transmit cycles on the R1 side (multi-cycle mode).
The following image shows multi cycle mode:
l
Multiple cycles (one capture cycle and multiple transmit cycles) on the R1 side,
and
l
Two cycles (receive and apply) on the R2 side.
Figure 31 SRDF/A SSC cycle switching – multi-cycle mode
Primary Site Secondary Site
Capture
cycle
Apply
cycle
N-M Transmit
cycle
Receive
cycle
Capture
N
Transmit
N-M
R1
R2
Receive
N-M
Transmit queue
depth = M
Transmit
N-1
Apply
N-M-1
R1
R2
In multi-cycle mode, each cycle switch creates a new capture cycle (N) and the
existing capture cycle (N-1) is added to the queue of cycles (N-1 through N-M cycles)
to be transmitted to the R2 side by a separate commit action.
Only the data in the last transmit cycle (N-M) is transferred to the R2 side during a
single commit.
Enginuity 5773 through 5876
SRDF/A SSC sessions that include an array running Enginuity 5773 through 5876 have
one Capture cycle and one Transmit cycle on the R1 side (legacy mode).
Remote replication solutions
SRDF write operations 129