VxVM: Restoration method from SNAPDONE plex to mirror volume

Asset ID:	1-71-1007974.1
Update Date:	2010-09-13
Keywords:

Solution Type Technical Instruction Sure

Solution 1007974.1 : VxVM: Restoration method from SNAPDONE plex to mirror volume

Example

In the following example, VxVM is used to create mirrored volumes from Logical
Unit Numbers(LUNs), presented from Sun StorEdge[TM] T3 Array arrays. Before the
problem, a snapshot was performed on the volumes. At some point after the
snapshot, a hardware issue caused the enabled/active plexes from the Sun
StorEdge T3 Arrays, to go into a NODEVICE state. The only remaining valid plex
on these volumes was the snapshot plex.

A vxprint of the diskgroup dg0 shows that there are 2 plexes on these volumes,
that are in a DISABLED/NODEVICE state.

 Disk group: dg0

 TY NAME         ASSOC        KSTATE   LENGTH   PLOFFS   STATE    TUTIL0 PUTIL0
dg dg0          dg0          -        -        -        -        -       -

 dm c2t1d0s2     -            -        -        -        NODEVICE -       -
dm c3t0d0s2     c3t0d0s2     -        1000624128 -      -        -       -
dm c4t0d0s2     -            -        -        -        NODEVICE -       -

 v  vol11        fsgen        ENABLED  166748160 -       ACTIVE   -       -
pl vol11-01     vol11        DISABLED 166756352 -       NODEVICE -       -
sd c2t1d0s2-01  vol11-01     DISABLED 166756352 0       NODEVICE -       -
pl vol11-02     vol11        DISABLED 166756352 -       NODEVICE -       -
sd c4t0d0s2-01  vol11-02     DISABLED 166756352 0       NODEVICE -       -
pl vol11-04     vol11        ENABLED  166756352 -       SNAPDONE -       -
sd c3t0d0s2-01  vol11-04     ENABLED  166756352 0       -        -       -

 v  vol12        fsgen        ENABLED  166748160 -       ACTIVE   -       -
pl vol12-01     vol12        DISABLED 166756352 -       NODEVICE -       -
sd c4t0d0s2-02  vol12-01     DISABLED 166756352 0       NODEVICE -       -
pl vol12-02     vol12        DISABLED 166756352 -       NODEVICE -       -
sd c2t1d0s2-03  vol12-02     DISABLED 166756352 0       NODEVICE -       -
pl vol12-04     vol12        ENABLED  166756352 -       SNAPDONE -       -
sd c3t0d0s2-02  vol12-04     ENABLED  166756352 0       -        -       -

Steps To recover:

1. Check and resolve the hardware issue that caused the Volume Manager
problem.  Do not attempt recovery until you are certain that the hardware
issue has been resolved.

2. Change the status of snapshot plex from SNAPDONE to ACTIVE using the vxplex
command shown below:

   # vxplex [-g diskgroup] convert state=ACTIVE plex

   # vxplex convert state=ACTIVE vol11-04
# vxplex convert state=ACTIVE vol12-04

3. Check that the status has indeed changed, by doing another     vxprint

  Disk group: dg0

  TY NAME         ASSOC        KSTATE   LENGTH   PLOFFS   STATE    TUTIL0 PUTIL0
dg dg0          dg0          -        -        -        -        -       -

  dm c2t1d0s2     -            -        -        -        NODEVICE -       -
dm c3t0d0s2     c3t0d0s2     -        1000624128 -      -        -       -
dm c4t0d0s2     -            -        -        -        NODEVICE -       -

  v  vol11        fsgen        ENABLED  166748160 -       ACTIVE   -       -
pl vol11-01     vol11        DISABLED 166756352 -       NODEVICE -       -
sd c2t1d0s2-01  vol11-01     DISABLED 166756352 0       NODEVICE -       -
pl vol11-02     vol11        DISABLED 166756352 -       NODEVICE -       -
sd c4t0d0s2-01  vol11-02     DISABLED 166756352 0       NODEVICE -       -
pl vol11-04     vol11        ENABLED  166756352 -       ACTIVE   -       -
sd c3t0d0s2-01  vol11-04     ENABLED  166756352 0       -        -       -

  v  vol12        fsgen        ENABLED  166748160 -       ACTIVE   -       -
pl vol12-01     vol12        DISABLED 166756352 -       NODEVICE -       -
sd c4t0d0s2-02  vol12-01     DISABLED 166756352 0       NODEVICE -       -
pl vol12-02     vol12        DISABLED 166756352 -       NODEVICE -       -
sd c2t1d0s2-03  vol12-02     DISABLED 166756352 0       NODEVICE -       -
pl vol12-04     vol12        ENABLED  166756352 -       ACTIVE   -       -
sd c3t0d0s2-02  vol12-04     ENABLED  166756352 0       -        -       -

4. Since Volume Manager sees the original subdisks as state NODEVICE, use
vxdiskadm option #5 to replace failed or removed disk.  This will reattach
the plex to the volume and initiate a resync from the remaining good plex.

5. Reset the original state of SNAPDONE on the plexes made ACTIVE in step 2
using the following vxplex command:

   vxplex [-g diskgroup] convert state=SNAPDONE plex

   # vxplex convert state=SNAPDONE vol11-04
# vxplex convert state=SNAPDONE vol12-04

Product
VERITAS Volume Manager 3.0.2 Software
Sun StorageTek T3 Array
Sun StorageTek T3+ Array

VxVM, Volume Manager, snapdone, plex
Previously Published As
82303

Change History
Date: 2005-08-04
User Name: 18392
Action: Approved
Comment: Added product names, product nouns, trademarking, STM, did some re-wording and formatting for clarity and readability.
Version: 3
Date: 2005-08-03
User Name: 18392
Action: Accept
Comment:
Version: 0
Date: 2005-08-03
User Name: 119902
Action: Approved
Comment: I have reviewed this document, made many necessary changes and submit it for final reveiw.
Version: 0
Product_uuid
a99f8f3a-2bd5-11d6-87a3-e467d9c55f5e|VERITAS Volume Manager 3.0.2 Software
2a6d7d50-0a18-11d6-8e0b-f0bd33b24928|Sun StorageTek T3 Array
2a714b10-0a18-11d6-86e2-d56b387d4fbf|Sun StorageTek T3+ Array

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