CTG 127 behavior and restrictions when a pair is suspended

TrueCopy® User Guide

Version
9.8.7
Audience
anonymous
Part Number
MK-98RD9022-18

Note the following behaviors and restrictions regarding the consistent suspending of all P-VOLs when a pair suspends.

  • When a failure occurs or if a pair is suspended by CCI, all P-VOLs will be suspended.
  • When P-VOLs and S-VOLs are registered in CTG 127, and both volumes are paired bidirectionally, all of the target pair volumes are registered in CTG 127 when takeover takes place.
  • The maximum number of pairs in CTG 127 is 4,096.
  • For P-VOLs to be suspended, a failure must occur, and then a write I/O operation must occur in any of the pairs.
  • When P-VOL status is PAIR and S-VOL status is PSUE, if a write I/O is executed, all P-VOLs registered in CTG 127 are suspended by failure.

    When P-VOL status is PAIR and S-VOL status is PSUE, you can restore PAIR status to the S-VOL by suspending the P-VOL and then resynchronizing the pair. With CCI, use the -l option.

  • When the S-VOL is suspended due to an intermittent communication failure, the P-VOL might not be suspended (P-VOL with no I/O processing stays in PAIR).