The pair status for all of the SI pairs in the CTG determines if you can perform a consistency group (CTG) pair-split. If all of the SI pairs in the CTG are paired (PAIR status), you can perform a CTG pair-split.
The following table describes when you can perform a CTG pair-split, based on the SI pairs in the CTG that are not paired (a status other than PAIR), and the resulting pair status after you perform the pair-split.
|
Status of pairs in the CTG other than PAIR |
Can you perform a CTG pair-split? |
Status after you perform a CTG pair-split |
|---|---|---|
|
COPY(PD) |
YES |
PSUS |
|
COPY(SP) |
YES2 |
PSUS |
|
PSUS(SP) |
YES2 |
PSUS |
|
PSUS |
YES2 |
PSUS |
|
COPY(RS) |
NO The command ends abnormally and shows the following information: [EX_CMDRJE] An order to the control/command device was rejected1 |
The pair statuses remain the same. |
|
COPY(RS-R) |
NO The command ends abnormally and shows the following information: [EX_CMDRJE] An order to the control/command device was rejected1 |
The pair statuses remain the same. |
|
PSUE |
NO The command ends abnormally and shows the following information: [EX_CMDRJE] An order to the control/command device was rejected |
The pair statuses remain the same. |
|
Notes:
|
||
The following are examples of when you can perform a CTG pair-split based on status of the SI pairs in the CTG:
- Example 1
The are six SI pairs in a CTG. Two of the pairs are paired (PAIR status), two are in COPY status, and two are in PSUS status. In this case, you can perform a CTG pair-split, and doing so changes the status of all of the pairs in the CTG to PSUS. However, the S-VOLs that were in PSUS might not be consistent with the other volumes in the CTG.
- Example 2
There are two SI pairs in a CTG and one is paired (PAIR status) and the other is in the process of being resynchronized (COPY status). In this case, you cannot perform a CTG pair-split.
- Example 3
The are six SI pairs in a CTG. Two of the pairs are paired (PAIR status), two are in the process of Quick Split (PSUS status), and two are in PSUE status. In this case, the CTG pair-split ends abnormally and the status of all of the pairs in the CTG remains the same.