HP Volume Shadowing for OpenVMS: OpenVMS Version 8.4 > Chapter 8 Host-Based Minimerge (HBMM)

Examples of Multiuse and Dismount

Example 8-1 Using MULTIUSE and DISMOUNT Keywords (I)

$ SET SHADOW DSA1/POLICY=HBMM=(MASTER=*,COUNT=12,MULTIUSE=12,DISMOUNT=1)

In this example, a policy is set in which all 12 bitmaps can be used as multiuse bitmaps. When you execute the command DISMOUNT/POLICY=MINICOPY, 1 minimerge bitmap is converted to multiuse bitmap. You can use this multiuse bitmap with the MINICOPY command to add the dismounted member back to the shadow set. In other words, it specifies that all 12 bitmaps can be used during the automatic and 1 bitmap during the manual removal of the shadow set member.

$ SHOW SHADOW


_DSA1:    Volume Label: DDD
  Virtual Unit State:   Steady State
  Enhanced Shadowing Features in use:
        Host-Based Minimerge (HBMM)
        Automatic Minicopy (AMCVP)
        Dismount uses Multiuse Bitmaps

  VU Timeout Value      3600    VU Site Value          0
  Copy/Merge Priority   5000    Mini Merge       Enabled
  Recovery Delay Per Served Member                    30
  Merge Delay Factor     200    Delay Threshold      200

  HBMM Policy
    HBMM Reset Threshold: 1000000
    HBMM Master lists:
      Up to any 12 nodes in the cluster - Multiuse: 12 Dismount: 1
    HBMM bitmaps are active on NODEA,KRISNA,MEERAA
    Modified blocks since bitmap creation: 0

  Device $1$MDA50               Master Member
    Read Cost              1    Site 0
    Member Timeout       120

  Device $1$MDA51
    Read Cost              1    Site 0
    Member Timeout       120

$ SHOW DEV/BIT
Device         BitMap     Size     Percent     Type of   Master  Active
 Name            ID      (Bytes)  Populated    Bitmap     Node
DSA1:         000A0001        12      0.01%   Minimerge  NODEA     Yes
              000A0002        12      0.01%   Minimerge  KRISNA    Yes
              00090003        12      0.01%   Minimerge  MEERAA    Yes

$ SHOW DEV DSA1

Device                  Device           Error    Volume         Free  Trans Mnt
 Name                   Status           Count     Label        Blocks Count Cnt
DSA1:                   Mounted              0  DDD              10139     1   3
$1$MDA50:      (NODEA)  ShadowSetMember      0  (member of DSA1:)
$1$MDA51:      (NODEA)  ShadowSetMember      0  (member of DSA1:)
NODEA$dismount $1$MDA51:/poli=mini

$ SHOW DEV/BIT
Device         BitMap     Size     Percent     Type of   Master  Active
 Name            ID      (Bytes)  Populated    Bitmap     Node
DSA1:         000A0001        12      0.01%   Multiuse   NODEA     Yes
              000A0002        12      0.01%   Minimerge  KRISNA    Yes
              00090003        12      0.01%   Minimerge  MEERAA    Yes
$

Example 8-2 Using MULTIUSE and DISMOUNT Keywords (II)

$ SET SHADOW DSA10/POLICY=HBMM=((MASTER=(*),COUNT=12,MULTIUSE=12,DISMOUNT=12))

In this example, a policy is set in which all 12 bitmaps can be used as multiuse bitmaps. When you execute the command DISMOUNT/POLICY=MINICOPY, 12 minimerge bitmaps are converted to multiuse bitmaps. You can use this multiuse bitmap with the MINICOPY command to add the dismounted member back to the shadow set. In other words, it specifies that 12 bitmaps can be used during the automatic or manual removal of the shadow set member.

$SHOW DEVICE DSA10/BIT
 
Device         BitMap     Size     Percent     Type of   Master  Active
 Name            ID      (Bytes)  Populated    Bitmap     Node
DSA10:	  00010085      6196      0.01%   Minimerge  LEXUS     Yes
              00010086      6196      0.01%   Minimerge  DARWIN    Yes
              00010087      6196      0.01%   Minimerge  NAPALM    Yes
              00010088      6196      0.01%   Minimerge  SPIFF     Yes
              00010089      6196      0.01%   Minimerge  CALVIN    Yes
              0001008A      6196      0.01%   Minimerge  LOPEZ     Yes
              0001008B      6196      0.01%   Minimerge  OBELIX    Yes
              0001008C      6196      0.01%   Minimerge  KRUSTY    Yes
              0001008D      6196      0.01%   Minimerge  GIMLI     Yes
              0001008E      6196      0.01%   Minimerge  HOMER     Yes
              0001008F      6196      0.01%   Minimerge  OOTY      Yes
              00010090      6196      0.01%   Minimerge  HOBBES    Yes

$DISMOUNT $1$DGA4996:  /POLICY=MINI
$SHOW DEVICE DSA10/bit
Device         BitMap     Size     Percent     Type of   Master  Active
 Name            ID      (Bytes)  Populated    Bitmap     Node
DSA10:        00010085      6196      0.01%   Multiuse   LEXUS     Yes                      
              00010086      6196      0.01%   Multiuse   DARWIN    Yes
              00010087      6196      0.01%   Multiuse   NAPALM    Yes
              00010088      6196      0.01%   Multiuse   SPIFF     Yes
              00010089      6196      0.01%   Multiuse   CALVIN    Yes
              0001008A      6196      0.01%   Multiuse   LOPEZ     Yes
              0001008B      6196      0.01%   Multiuse   OBELIX    Yes
              0001008C      6196      0.01%   Multiuse   KRUSTY    Yes
              0001008D      6196      0.01%   Multiuse   GIMLI     Yes
              0001008E      6196      0.01%   Multiuse   HOMER     Yes
              0001008F      6196      0.01%   Multiuse   OOTY      Yes
              00010090      6196      0.01%   Multiuse   HOBBES    Yes

When the minicopy completes and the dismounted member is added back to the shadow set, the “multiuse” bitmap is converted to the “minimerge” bitmap.

$SHOW DEVICE DSA301/BIT
Device         BitMap     Size     Percent     Type of   Master  Active
 Name            ID      (Bytes)  Populated    Bitmap     Node
DSA301:       00010085      6196      0.01%   Minimerge  LEXUS     Yes
              00010086      6196      0.01%   Minimerge  DARWIN    Yes
              00010087      6196      0.01%   Minimerge  NAPALM    Yes
              00010088      6196      0.01%   Minimerge  SPIFF     Yes
              00010089      6196      0.01%   Minimerge  CALVIN    Yes
              0001008A      6196      0.01%   Minimerge  LOPEZ     Yes
              0001008B      6196      0.01%   Minimerge  OBELIX    Yes
              0001008C      6196      0.01%   Minimerge  KRUSTY    Yes
              0001008D      6196      0.01%   Minimerge  GIMLI     Yes
              0001008E      6196      0.01%   Minimerge  HOMER     Yes
              0001008F      6196      0.01%   Minimerge  OOTY      Yes
              00010090      6196      0.01%   Minimerge  HOBBES    Yes

The following example shows that using any further commands to create bitmaps fails because all the 12 bitmap slots are utilized.

$DISM $1$DGA4993:  /POLICY=MINI
%DISM-W-CANNOTDMT, $1$DGA4993: cannot be dismounted  
%SYSTEM-F-WBMERR, WBM error during dismount