Recovering from a failure (LDEV blockade) on an S-VOL at the secondary site (GAD+UR)

Global Active Device for VSP One Block

Version
10.5.x
File Size
25537 KB
Audience
anonymous
Part Number
MK-23VSP1B011-11
ft:lastEdition
2026-06-23

When a failure (LDEV blockade) occurs on an S-VOL at the secondary site, the GAD pair statuses of the P-VOL and S-VOL change to PSUE.

Overview of failure recovery



  1. Remove the failure (LDEV blockade) on the S-VOL.
  2. If the S-VOL must be formatted for restoration, delete the GAD pair, and then format the S-VOL.
  3. Depending on if you performed step 2, re-create the GAD pair, the delta resync UR pair, and the UR pair in that order, or resynchronize the GAD pair in the primary storage system.
    • If you performed step 2, re-create the GAD pair, the delta resync UR pair, and the UR pair in that order.

      If a failure occurs after the one volume capacity of a GAD pair or UR pair can be expanded, the creation, resync, swap resync, horctakeover, and delta resync operations of the GAD pair or UR pair cannot be performed because the capacity of both the volumes is not the same. Make sure to expand the other volume capacity so that the capacity of both the volumes is the same, and then retry the operation.

      Command example:

      paircreate -g oraHA -fg never 2 -vl -jq 0 -IH0
      paircreate -g oraDELTA -f async -vl -jp 0 -js 0 -nocsus -IH1
      paircreate -g oraREMOTE -f async -vl -jp 0 -js 0 -IH0
    • If you did not perform step 2, resynchronize the GAD pair in the primary storage system.

      If a failure occurs after the one volume capacity of a GAD pair can be expanded, the creation, resync, swap resync, and horctakeover operations of the GAD pair cannot be performed because the capacity of both the volumes is not the same. Make sure to expand the other volume capacity so that the capacity of both the volumes is the same, and then retry the operation.

      Command example:

      pairresync -g oraHA -IH0
  4. Confirm that the GAD P-VOL and S-VOL pair statuses change to PAIR.

    Command example:

    pairdisplay -g oraHA -fxce -IH0
    Group   PairVol(L/R) (Port#,TID, LU),Seq#,LDEV#.P/S,Status,
    Fence,   %,P-LDEV# M CTG JID AP EM       E-Seq# E-LDEV# R/W
    oraHA   dev1(L)     (CL1-A-0, 0,   0)811111  2222.P-VOL PAIR 
    NEVER ,  100  4444 -   -   0  -  -            -       - L/M
    oraHA   dev1(R)     (CL1-C-0, 0,   0)822222  4444.S-VOL PAIR 
    NEVER ,  100  2222 -   -   0  -  -            -       - L/M
    pairdisplay -g oraHA -fxce -IH1
    Group   PairVol(L/R) (Port#,TID, LU),Seq#,LDEV#.P/S,Status,
    Fence,   %,P-LDEV# M CTG JID AP EM       E-Seq# E-LDEV# R/W
    oraHA   dev1(L)     (CL1-C-0, 0,   0)822222  4444.S-VOL PAIR 
    NEVER ,  100  2222 -   -   0  -  -            -       - L/M
    oraHA   dev1(R)     (CL1-A-0, 0,   0)811111  2222.P-VOL PAIR 
    NEVER ,  100  4444 -   -   0  -  -            -       - L/M
  5. Keep updating I/O from the server to the P-VOL or S-VOL of the GAD pair for about two minutes.
  6. Confirm that the status of the UR delta resync P-VOL is PSUS.

    Command example:

    pairdisplay -g oraDELTA -fxce -IH1
    Group     PairVol(L/R)  (Port#,TID, LU),Seq#,  LDEV#.P/S,  
    Status,Fence, %,  P-LDEV#  M  CTG  JID  AP  EM  E-Seq#  E-LDEV#  R/W
    oraDELTA  dev3(L)       (CL1-A-1, 0, 1) 822222 4444. P-VOL 
    PSUS   ASYNC ,0   6666     -  0    0    -   -   -       -       -/-
    oraDELTA  dev3(R)       (CL1-A-1, 0, 1) 844444 6666. S-VOL 
    SSUS   ASYNC ,0   4444     -  0    0    -   -   -       -       -/-
  7. Confirm that the mirror status of the journal of the UR delta resync pair is PJNS using the CCI instance for managing the GAD secondary storage system.

    Command example:

    pairdisplay -g oraDELTA -v jnl -IH1
    JID  MU  CTG  JNLS  AP  U(%)  Q-Marker  Q-CNT  D-SZ(BLK)  Seq#   Num  LDEV#
    000  1   1    PJNS  4   21    43216fde  30     512345     62500  1    39321 
  8. Confirm that no failure SIMs are displayed.