The SHOW DEVICE, SHOW CLUSTER, and DELETE commands
have been extended for managing bitmaps.
Determining Bitmap Support and Activity
You can find out whether a bitmap exists for a
shadow set by using the DCL command SHOW DEVICE/FULL device-name. If a shadow set supports bitmaps, device
supports bitmaps is displayed along with either bitmaps active or no
bitmaps active. If the device does not support bitmaps,
no message pertaining to bitmaps is displayed.
The following command example shows that no bitmap
$ SHOW DEVICE/FULL DSA0
Disk DSA0:, device type RAM Disk, is online, mounted, file-oriented device,
shareable, available to cluster, error logging is enabled, device supports
bitmaps (no bitmaps active).
Error count 0 Operations completed 47
Owner process ““ Owner UIC [SYSTEM]
Owner process ID 00000000 Dev Prot S:RWPL,O:RWPL,G:R,W
Reference count 2 Default buffer size 512
Total blocks 1000 Sectors per track 64
Total cylinders 1 Tracks per cylinder 32
Volume label “TST0” Relative volume number 0
Cluster size 1 Transaction count 1
Free blocks 969 Maximum files allowed 250
Extend quantity 5 Mount count 1
Mount status System Cache name “_$252$DUA721:XQPCACHE”
Extent cache size 64 Maximum blocks in extent cache 96
File ID cache size 64 Blocks currently in extent cache 0
Quota cache size 0 Maximum buffers in FCP cache 404
Volume owner UIC [SYSTEM] Vol Prot S:RWCD,O:RWCD,G:RWCD,W:RWCD
Volume Status: ODS-2, subject to mount verification, file high-water marking, write-through
XQP caching enabled, write-through XFC caching enabled.
Disk $252$MDA0:, device type RAM Disk, is online, member of shadow set DSA0:.
Error count 0 Shadow member operation count 128
Allocation class 252
Disk $252$MDA1:, device type RAM Disk, is online, member of shadow set DSA0:.
Error count 0 Shadow member operation count 157
Allocation class 25
Displaying Bitmap IDs
You can find out the ID of each bitmap on a node with the DCL command
SHOW DEVICE/BITMAP device-name. The /BITMAP qualifier
cannot be combined with other SHOW DEVICE qualifiers except /FULL.
The SHOW DEVICE/BITMAP display can be brief or full; brief is the
If no bitmap is active, no bitmap ID is displayed.
The phrase no bitmaps active is displayed.
The following example shows a SHOW DEVICE/BITMAP
$ SHOW DEVICE/BITMAP DSA1
Device BitMap Size Percent of
Name ID (Bytes) Full Copy
DSA1: 00010001 652 11%
The following example shows a SHOW DEVICE/BITMAP/FULL
$ SHOW DEVICE DSA12/BITMAP/FULL
Device Bitmap Size Percent of Active Creation Master Cluster Local Delete Bitmap
Name ID (bytes) Full Copy Date/Time Node Size Set Pending Name
DSA12: 00010001 652 11% Yes 5-MAY-2000 13:30...300F2 127 2% No SHAD$TEST
NOTE: The bitmap name, which is only displayed when
you specify SHOW/DEVICE/FULL, takes the form of SHAD$volume-name,
followed by many (about 30) unreadable characters. These unreadable
characters are used internally to represent the generation number
of the bitmap, the time it was created, and other details. The bitmap
name is only used internally. The bitmap ID is used by system managers.
Displaying Bitmap Status of Cluster Members
You can specify bitmap information in the SHOW
CLUSTER display by issuing the ADD BITMAPS command, as shown in the
$ SHOW CLUSTER/CONTINUOUS
Command > ADD BITMAPS
Command > ADD CSID
View of Cluster from system ID 57348 node: WPCM1 14-FEB-2000 13:38:53
NODE SOFTWARE CSID STATUS BITMAPS
CSGF1 VMS X6TF 300F2 MEMBER MINICOPY
HSD30Y HSD YA01 300E6
HS1CP2 HSD V31D 300F4
CSGF2 VMS X6TF 300D0 MEMBER MINICOPY
In this example, MINICOPY means that nodes CSGF1
and CSGF2 are capable of supporting minicopy operations. If a cluster
node does not support minicopy, the term UNSUPPORTED replaces MINICOPY
in the display, and the minicopy function is disabled in the cluster.
After a minicopy operation is completed, the corresponding
bitmap is automatically deleted.
There may be times when you would like to delete
one or more bitmaps. Reasons for deleting bitmaps include the following:
To recover the memory
consumed by a bitmap
To stop the recording
of the bitmap
You can delete bitmaps with the DCL command DELETE
with the /BITMAP qualifer. You use the bitmap qualifer to specify
the ID of the bitmap you want to delete. For example: