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.