Management of the use and require type of persistent attributes


Management of the use and require type of persistent attributes
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Persistent attributes are the saved volume intents that should be honored for subsequent allocation operations for that volume. The intent management operations enable you to manage the use and require type of persistent intents for volumes. These operations allow you to independently manage the intents after the volume creation. When you change the persistent intents for a volume, the changed intents are not checked for validity or enforced for the current allocation of the volume.

You can set, change, clear, or list the persistent intents for the volume with the following vxassist operations:

setrule

Replaces any existing saved intents with the specified intents for the specified volume.
changerule

Appends the specified intents to the existing saved intents for the specified volume.
clearrule

Removes any existing saved intents for the specified volume.
listrule

Lists any saved intents for the specified volume. If no volume name is specified, the command shows the intents for all of the volumes.

The intent management operations only apply to the use or require type of persistent constraints. The other type of persistent constraints are managed with the persist attribute.

See Using persistent attributes.

To display the intents that are currently associated to a volume

To display the intents that are currently associated to a volume, use the following command:

# vxassist [options] listrule [volume]

For example, to display the existing saved intents for the volume v1:

# vxassist -g testdg listrule v1
volume rule v1 {                              
     require=array:ams_wms0               
}

To replace the intents that are currently associated to a volume

Display the intents that are currently associated to the volume:
```
# vxassist [options] listrule [volume] 
```
In this example, the volume v1 has an existing saved intent that requires the array to be ams_wms0. For example, to display the existing saved intents for the volume v1:
```
# vxassist -g testdg listrule v1
volume rule v1 {                              
     require=array:ams_wms0               
}
```
Specify the new intent with the following command:
```
# vxassist [options] setrule volume attributes...
```
For example, to replace the array with the ds4100-0 array, specify the new intent with the following command:
```
# vxassist -g testdg setrule v1 require=array:ds4100-0
```
Verify the new intent with the display command.
For example, the following command shows that the intent has changed:
```
# vxassist -g testdg listrule v1
volume rule v1 {
     require=array:ds4100-0
}
```

To add to the intents that are currently associated to a volume

Display the intents that are currently associated to the volume:
```
# vxassist [options] listrule [volume] 
```
In this example, the volume v1 has an existing saved intent that requires the array to be ds4100-0. For example, to display the existing saved intents for the volume v1:
```
# vxassist -g testdg listrule v1
volume rule v1 {                              
     use=array:ds4100-0             
}
```
Add the new intent with the following command:
```
# vxassist [options] changerule volume attributes...
```
For example, to add the ams_wms0 array in the use constraint, specify the new intent with the following command:
```
# vxassist -g testdg changerule v1 use=array:ams_wms0
```
Verify the new intent with the display command.
For example, the following command shows that the intent has changed:
```
# vxassist -g testdg listrule v1
volume rule v1 {
     use=array:ds4100-0,array:ams_wms0
}
```

To clear the intents that are currently associated to a volume

Display the intents that are currently associated to the volume:

# vxassist [options] listrule [volume]

For example, to display the existing saved intents for the volume v1:

# vxassist -g testdg listrule v1
volume rule v1 {
     require=multipathed:yes
     use=array:emc_clariion0,array:ams_wms0
}

Clear the existing intents with the following command:
```
# vxassist [options] clearrule volume 
```
For example, to clear the intents for the volume v1:
```
# vxassist -g testdg clearrule v1
```
Verify that the volume has no saved intents.
For example, the following command shows that the volume v1 has no saved intents:
```
# vxassist -g testdg listrule v1
volume rule v1 {}
```

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