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

About TrueCopy for z/OS Operations 2-27
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
100%
70%
60%
50%
45%
40%
35%
30%
Puncture Threshold = ST+10%
Sidefile Threshold (ST)
High-Water Mark = ST-20%
Host Write I/O delayed
500 ms for every write if Mode 93=OFF
100 ms for every write if Mode 93=ON
until below threshold.
Long Delay Type Short Delay Type
Mode 93 = OFF Mode 93 = ON
+400ms X1 delay
+300ms X1 delay
+200ms X1 delay
+100ms X1 delay
+80ms X 1 delay
+60ms X 1 delay
+40ms X 1 delay
+20ms X 1 delay
Sidefile Threshold (ST) = 30% to 70% user-specified
Example: Threshold = 50% (default)
SIM generated at HWM when mode 118 or 464 is
ON.
SIM ref code = 490x, x = CU
This SIM is reported per CLPR every 30 sec.
as long as condition exists.
Suspend TCzA pairs at puncture
due to sidefile overflow condition.
Figure 2-4 Graduated Delay Process for Sidefile Management