Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

Performing TrueCopy for z/OS Configuration Operations 5-15
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
The default value of Round Trip Time is 1 ms. You may specify 1 ms to 500
ms. You can use the following formula to figure out the Round Trip Time.
Round Trip time = Round Trip Time between MCU-RCU x 2
(*)
+ Initial Copy response time (ms)
(*)
A data transfer between MCU and RCU involves two response sequences in one command issuance. Therefore, you
need to double the Round Trip Time between MCU-RCU.
For Round Trip Time between MCU and RCU, please ask your carrier, or use a
ping command and etc. to measure the time. If you do not use lines etc.
between MCU and RCU, specify “1”.
Initial Copy response time is the response time required for multiple initial
copy operations. You can use the following formula to get the Initial Copy
response time. To get the time, you should use the following values: the initial
copy pace, the max number of maximum initial copy VOLs, the speed of the
line between MCU and RCU, and the number of lines.
Initial Copy response time (ms) = (1[MB] / “Speed of line between MCU-
RCU[MB/ms]
(*1)
”)
x (“initial copy pace”
(*2)
/ 15)
x (“max number of maximum initial copy VOLs
(*3)
” / “Number of lines between MCU-RCU”
(*4)
)
(*1)
When you connect MCU with RCU without lines etc., specify 0.17[MB/ms] in “Speed of line between MCU and
RCU”.
(*2)
For “initial copy pace” in the formula above, see Table 5-1.
(*3)
For “the maximum number of maximum initial copy volumes”, use the value set up per disk subsystem. The
default is 64.
(*4)
Even if “Max number of maximum initial copy VOLs” / “Number of lines between MCU-RCU” is larger than 16,
specify “Max number of maximum initial copy VOLs” / “Number of lines between MCU-RCU” as 16.
Table 5-1 Initial Copy Pace for Calculating The Initial Copy Response
Time
Perform Initial Copy and Update Copy at a Time Operation Perform Initial Copy Only
Initial Copy Pace Specified at
the Time of Pair Creation is
1 to 8
Initial Copy Pace Specified at the
Time of Pair Creation
9 to 15
Storage
Navigator
Initial copy pace specified
at the time of pair
creation
Initial copy pace specified at the
time of pair creation
8
Business
Continuity
Manager
Initial copy pace specified
at the time of pair
creation
Initial copy pace specified at the
time of pair creation
8
PPRC command
(TSO/ICKDSF)
and CU emulation
type=3990
Initial copy pace specified
at the time of pair
creation
Initial copy pace specified at the
time of pair creation
8