HELPLIB.HLB  —  SHOW  SHADOW
    Valid for Alpha and Integrity server systems only.

    Displays the status of a specified shadow set on the system.

    If no qualifiers are specified, displays a summary of the device.

    Format

      SHOW SHADOW  [DSAn[:]]

1  –  Parameter

 DSAn[:]

    Specifies the virtual unit name of the shadow set for which
    information is to be displayed.

    If no virtual unit is specified, information is displayed for all
    mounted shadow sets.

2  –  Qualifiers

2.1    /ACTIVE

    Displays one of three possible states:

    o  Merge or Copy is not required

    o  Copy is in progress on node node-name, n% completed

    o  Merge is in progress on node node-name, n% completed

2.2    /BY_PRIORITY

       /BY_PRIORITY
       /BY_PRIORITY DSAn:

    Displays a list of shadow sets on the system, sorted in the order
    in which a recovery operation (copy, full merge, or minimerge)
    is scheduled to occur. If a copy or merge is active, the display
    shows on which system it is occurring. This list is specific to
    the system on which the command is executed, so the list might
    vary across systems in a cluster. Higher numbers indicate a
    higher priority.

    Tip: When the command specifies a virtual unit (DSAn:), the
    display shows the current priority and status of just this
    virtual unit. If any copy or merge operations are in progress,
    the system on which the operation is occurring is also displayed,
    along with the operation's progress.

2.3    /COPY

    Displays one of three possible states:

    o  Copy is not required

    o  Copy is pending

    o  Copy is in progress on node node-name, n% completed

2.4    /FULL

    Displays complete information about the specified devices (or all
    devices if no device is specified). The only other qualifier that
    can be specified with /FULL is /OUTPUT.

2.5    /MERGE

    Displays one of three possible states:

    o  Merge is not required

    o  Merge is pending

    o  Merge is in progress on node node-name, n% completed

2.6    /NAME

       /NAME[=policy-name]

    Used with /POLICY=HBMM to display the characteristics of a
    specific, named host-based minimerge (HBMM) policy or, if no
    policy name is specified, all named HBMM policies on the cluster.

2.7    /OUTPUT

       /OUTPUT[=filespec]

    Outputs any messages to the specified file.

2.8    /POLICY

       /POLICY=HBMM

    Displays the host-based minimerge (HBMM) policy associated with
    the specified devices.

    HBMM is the only value supported for /POLICY, and it must be
    included.

    If the command is issued with no device specification,
    information is output for all devices. There might be a
    noticeable delay between the output of device information or
    before returning to the DCL command prompt. This delay is normal.

2.9    /SITE

       /SITE=n

    Displays every shadow set member device (and the virtual device
    of which it is a member) that has the site value specified by n.

3  –  Examples

    1.$ SHOW SHADOW DSA112:
      _DSA112:  Volume Label: DSA112
        Virtual Unit State:   Steady State
        No Enhanced Shadowing Features in use

        VU Timeout Value      1200    VU Site Value          0
        Copy/Merge Priority   5000    Mini Merge      Disabled
        Served Path Delay     30

        Device $1$DGA112              Master Member
          Read Cost             2     Site 0
          Member Timeout        180

        Device $1$DGA113
          Read Cost             2     Site 0
          Member Timeout        180

      This display is for a shadow set that is in a steady state.
      That is, there are no active or pending merges or copy
      operations for this shadow set and HBMM has not been enabled.

    2.$ SHOW SHADOW DSA112:
      _DSA112:  Volume Label: DSA112
      Virtual Unit State: MiniMerge Active (5%),Copy Pending (32%) on NODE1
        Enhanced Shadowing Features in use:
            Host-Based Minimerge (HBMM)

        VU Timeout Value      1200    VU Site Value          0
        Copy/Merge Priority   5000    Mini Merge       Enabled
        Served Path Delay     30

        HBMM Policy
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 6 nodes in the cluster
          HBMM bitmaps are active on NODE1,NODE2
          Modified blocks since bitmap creation: 137033

        Device $1$DGA112              Master Member, Merging (5%)
          Read Cost             2     Site 0
          Member Timeout        180

        Device $1$DGA113              Copy Target (32%)
          Read Cost             2     Site 0
          Member Timeout        180

      This display is for a shadow set that is enabled for HBMM. A
      shadow set member copy and a shadow set merge are required for
      this shadow set. The shadow member copy was 32% complete when a
      merge became necessary. Because the merge was a minimerge, it
      preempted the copy and the status of the copy now displays as
      pending.

    3.$ SHOW SHADOW DSA12

      _DSA12:   Volume Label: DGA12
        Virtual Unit State: Merge Active (23%), Copy Pending (3%) on NODE1
        Enhanced Shadowing Features in use:
            Host-Based Minimerge (HBMM)

        VU Timeout Value      300     VU Site Value          5
        Copy/Merge Priority   5000    Mini Merge       Enabled
        Served Path Delay     0

        HBMM Policy
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 2 of the nodes: NODE1,NODE2
          HBMM bitmaps are active on the following nodes: NODE2,NODE1
        Modified blocks since bitmap creation: 254

        Device $1$DGA12               Master Member, Merging (23%)
          Read Cost             2     Site 5
          Member Timeout        180

        Device $1$DGA22               Copy Target (3%)
          Read Cost             2     Site 0
          Member Timeout        180

        Device $1$DGA32               Merging (23%)
          Read Cost             2     Site 0
          Member Timeout        180

      This example displays status information for shadow set DSA12.
      A minimerge operation takes precedence over a copy operation,
      so the copy has been stopped at 3 percent and the merge is now
      active and 23 percent completed.

      Note that the VU site value and the site value for device
      $1$DGA12 are both 5. Therefore, read I/O to DSA12 on this
      system is directed to $1$DGA12.

    4.$ SHOW SHADOW /BY_PRIORITY
      Device    Mbr                                        Active
       Name     Cnt  Priority Virtual Unit State          on Node
      _DSA30:    2     5000   Steady State
      _DSA12:    3     4000   Steady State
      _DSA234:         3000   Not Mounted on this node
      Total of 2 Operational shadow sets; 0 in Mount Verification;
      1 not mounted

      The display resulting from this command shows that device DSA30
      (with a priority of 5) will start a copy or merge operation
      on this system before DSA12 (with a priority of 4). It also
      shows that DSA30 is a two-member shadow set and that DSA12: is
      a three-member shadow set.

      The last line of the display summarizes all the shadow sets and
      their states, including shadow sets that have exceeded their
      mount verification timeout limits. Operational shadow sets are
      shadow sets that are mounted with one or more members and that
      may or may not have copy or merge operations in progress. These
      shadow sets are available to applications for reads and writes.

    5.$ SHOW SHADOW /BY_PRIORITY
      Device  Mbr                                               Active
       Name   Cnt Priority Virtual Unit State                  on Node
      _DSA30: 2+1   5000   Merge Pending (23%), Copy Active (5%) NODE1
      _DSA12:  2    4000   Steady State
      _DSA234:      3000   Not Mounted on this node
      Total of 2 Operational shadow sets; 0 in Mount Verification;
      1 not mounted

      This display shows that a copy is being performed on system
      NODE1 and is 5 percent done. The member count (Mbr Cnt) of 2+1
      indicates that there are two source members in the shadow set
      and another member is being added. The shadow set had completed
      23 percent of a merge when the third member was added. When
      the copy operation is complete, the merge will resume from that
      point.

    6.$ SHOW SHADOW /BY_PRIORITY DSA11
      Device    Mbr                                           Active
       Name     Cnt  Priority  Virtual Unit State            on Node
      _DSA11:    3     5000    Merge Active (29%)              NODE3

      This command displays the status of only DSA11, which is 29
      percent through a merge operation on NODE3.

    7.$ SHOW SHADOW /MERGE

      Device    Volume Name Status

      _DSA1010: FOOBAR      Merge Pending (23%), Copy Active (77%) on NODE1

      This command requests the status of a merge operation. The
      display provides the status of the merge, but also reveals that
      a copy operation is currently active.

    8.$ SHOW SHADOW DSA1010 /ACTIVE

      Device     Volume Name   Status

      _DSA1010:  FOOBAR        Merge Active (25%) on NODE1

      The copy shown to be in progress in the previous example has
      completed; now the merge has resumed and is 25 percent done.
      NODE1 is doing the merge.

    9.$ SHOW SHADOW DSA1010

      _DSA1010: Volume Label: FOOBAR
        Virtual Unit State:   Merge Pending (0%)
        Enhanced Shadowing Features in use:
            Host-Based Minimerge (HBMM)

        VU Timeout Value      3600    VU Site Value          0
        Copy/Merge Priority   5000    Mini Merge      Disabled
        Served Path Delay     30

        Device $252$DUA610            Master Member Merging (0%)
          Read Cost             2     Site 0
          Member Timeout        10

        Device $252$DUA1010     Merging (0%)
          Read Cost             2     Site 0
          Member Timeout        10

        Device $252$DUA716      Merging (0%)
          Read Cost             2     Site 0
          Member Timeout        10

      In this example, another event has caused the set to go into a
      merge state. However, this set is not currently being acted on
      - perhaps because the system does not have any more SHADOW_MAX_
      COPY threads or because the relative priority of this shadow
      set is lower, causing other merges to be completed first. When
      a system is able to perform the merge, the word Active appears
      in the display and the Merging percent begins to increase.)

    10$ SHOW SHADOW DSA12 /POLICY=HBMM

        HBMM Policy for device _DSA12:
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 2 of the nodes: NODE1,NODE2,NODE3
          HBMM bitmaps are active on the following nodes: NODE2,NODE1
        HBMM Reset Count      4      Last Reset  9-JAN-2004 13:40:11.45
        Modified blocks since last bitmap reset: 142367

      This command displays host-based minimerge (HBMM) information
      for device DSA12.

      In this example, an HBMM policy has been defined for DSA12. No
      more than two of the systems NODE1 and NODE2 can have master
      bitmaps for DSA12 at any time. The bitmap is reset when the
      bitmap has bits set to represent a total of 50000 blocks
      written to DSA12. When this command was entered, both NODE1
      and NODE2 had master bitmaps.

      Note that the "modified blocks" value exceeds that of the
      reset threshold. This can happen because the bitmap is not
      reset immediately upon crossing the reset threshold. The
      reset threshold is checked periodically, and the interval
      for checking the reset threshold is controlled by the system
      parameter SHADOW_HBMM_RTC; the default is 150 seconds.

    11$ SHOW SHADOW/POLICY=HBMM/NAME=PEAKS_ISLAND

         HBMM Policy PEAKS_ISLAND
           HBMM Reset Threshold: 50000
           HBMM Master lists:
             Up to any 2 of the nodes: NODE1,NODE2,NODE3
             Any 1 of the nodes: NODE4,NODE5
             Up to any 2 of the nodes: NODE6,NODE7,NODE8

      This command displays the HBMM named policy PEAKS_ISLAND.

    12$ SHOW SHADOW /POLICY=HBMM

         HBMM Policy for device _DSA12:
           HBMM Reset Threshold: 50000
           HBMM Master lists:
             Up to any 2 of the nodes: NODE1,NODE2
           HBMM bitmaps are active on NODE1,NODE2
         Modified blocks since bitmap creation: 254

         HBMM Policy for device _DSA30:
           HBMM Reset Threshold: 50000
           HBMM Master lists:
             Up to any 2 of the nodes: FLURRY,FREEZE,HOTTUB

         HBMM Policy for device _DSA99:
           HBMM Reset Threshold: 50000
           HBMM Master lists:
             Up to any 2 of the nodes: NODE1,NODE2,NODE3
             Any 1 of the nodes: NODE4,NODE5
             Up to any 2 of the nodes: ICEBAR,SWEDEN,MILANO

         HBMM Policy for device _DSA999:
           HBMM Reset Threshold: 50000
           HBMM Master lists:
             Up to any 2 of the nodes: NODE1,NODE2,NODE3
             Any 1 of the nodes: NODE4,NODE5
             Up to any 2 of the nodes: ICEBAR,SWEDEN,MILANO

      The command in this example displays a list of all shadow sets
      that have HBMM policies.

    13$ SHOW SHADOW /POLICY=HBMM /NAME

        HBMM Policy PEAKS_ISLAND
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 2 of the nodes: NODE1,NODE2,NODE3
            Any 1 of the nodes: NODE4,NODE5
            Up to any 2 of the nodes: NODE6,NODE7,NODE8

        HBMM Policy POLICY_1
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 2 of the nodes: NODE1,NODE2,NODE3
            Any 1 of the nodes: NODE4,NODE5

        HBMM Policy ICE_HOTELS
          HBMM Reset Threshold: 50000
            Up to any 2 of the nodes: QUEBEC,SWEDEN,FINLND
            Any 1 of the nodes: ALASKA,GRNLND

      The command in this example displays a list of all named HBMM
      policies on the cluster.

    14$ SHOW SHADOW DSA12 /OUTPUT=DSA12_OUTPUT.LIS

      The output of this SHOW SHADOW command is directed to the file
      named DSA12_OUTPUT.LIS.

    15$ SHOW SHADOW DSA12 /FULL

      _DSA12:   VolumeLabel: DGA12
        Virtual Unit State:  Steady State
        Enhanced Shadowing Features in use:
            Host-Based Minimerge (HBMM)

        Cluster Virtual Unit Status: 0001 - normal
        Local Virtual Unit Status: 00000110 - Local Read,Policy Active

        Total Devices         2       VU_UCB          81435180
        Source Members        2       SCB LBN         003FEB5F
        Act Copy Target       0       Generation      00A2BA31
        Act Merge Target      0        Number         441DA800
        Last Read Index       0       Master Mbr Index       0
        Copy Hotblocks        0       Copy Collisions        0
        SCP Merge Repair Cnt  0       APP Merge Repair Cnt   0
        VU Timeout Value      300     VU Site Value          0
        Copy/Merge Priority   5000    Mini Merge       Enabled
        Served Path Delay     0

        HBMM Policy
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 2 of the nodes: XYZ100,XYZ200
          HBMM bitmaps are active on the following nodes: XYZ200,XYZ100
        Modified blocks since bitmap creation: 254

        Device $1$DGA12               Master Member
          Index 0 Status  000000A0    src,valid
          Ext. Member Status    00
          Read Cost             2     Site 0
          Member Timeout        180   UCB  81643840

        Device $1$DGA22
          Index 1 Status  000000A0    src,valid
          Ext. Member Status    00
          Read Cost             2     Site 0
          Member Timeout        180   UCB  81642840

        Device $1$DGA32
          Index 1 Status 000000A0     src,valid
          Ext. Member Status    00
          Read Cost             2     Site  0
          Member Timeout        180   UCB  81641840

      This example shows a full information display for device DSA12.

    16$ SHOW SHADOW DSA0 /FULL

      _DSA0:    Volume Label: TOPAZ_XA7V
        Virtual Unit State:   Steady State
        Cluster Virtual Unit Status: 0001 - normal
        Local Virtual Unit Status: 00000110 - enforce_local_read,
      hbmm_eval_policy_enabled

        Enhanced Shadowing Features in use:
              Dissimilar Device Shadowing (DDS)
              Host-Based Minimerge (HBMM)

        Total Devices            2    VU_UCB          817AFD80
        Source Members           2    SCB LBN         001F5C50
        Act Copy Target          0    Generation      00A31141
        Act Merge Target         0     Number         C6925F29
        Last Read Index          0    Master Mbr Index       0
        Copy Hotblocks           0    Copy Collisions        0
        SCP Merge Repair Cnt     0    APP Merge Repair Cnt   0
        VU Timeout Value      3600    VU Site Value          0
        Copy/Merge Priority   5000    Mini Merge       Enabled
        Served Path Delay       30

        HBMM Policy
          HBMM Reset Threshold: 50000
          HBMM Master lists:
            Up to any 6 nodes in the cluster
          HBMM bitmaps are active on ABCD2,ABCD1
          Modified blocks since bitmap creation: 254

        Device $252$DKA0              Master Member
          Index 0 Status  000000A0    mbr_src,mbr_valid
          Ext. Member Status    00
          Read Cost              2    Site 0
          Member Timeout       120    UCB  8163D880

        Device $252$DKA100
          Index 1 Status  000000A0    mbr_src,mbr_valid
          Ext. Member Status    00
          Read Cost              2    Site 0
          Member Timeout       120    UCB  8163E880

      This example shows sample output when both HBMM and Dissimilar
      Device Shadowing are in use.
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