Changing Default Behavior of the metassist Command

You can use the volume defaults file (/etc/defaults/metassist.xml) to establish default behavior for the metassist command. By changing the defaults file, you can explicitly exclude—or include—disks or controllers from consideration, and additionally specify requirements for most volume settings used by the metassist command.

The format of the /etc/defaults/metassist.xml is specified by the /usr/share/lib/xml/dtd/volume-defaults.dtd Document Type Definition (DTD), and documented in volume-defaults(4).

Changing the Volume Defaults File

Edit the volume defaults file (/etc/defaults/metassist.xml) to specify how the metassist command should behave.

When you edit the file, you must ensure that the file continues to be compliant with the /usr/share/lib/xml/dtd/volume-defaults.dtd Document Type Definition. If the XML file is not compliant with the DTD, the metassist command will fail with an error message.

Example—Creating A Volume With Changed Defaults for the metassist Command

Before creating a volume, edit the /etc/default/metassist.xml file to specify the default settings that you want to apply to all volumes you will create with the metassist command. In this example, the metassist command will only create volumes on controller c1 and, when creating stripes, will only create stripes with exactly 4 components and an interlace of 512KB. These constraints will apply to all uses of the metassist command until the /etc/default/metassist.xml file is changed again.

#  cat /etc/default/metassist.xml 
<!DOCTYPE volume-defaults SYSTEM "/usr/share/lib/xml/dtd/volume-defaults.dtd">

<volume-defaults>
<available name="c1" />
<stripe mincomp="4" maxcomp="4" interlace="512KB" ></stripe>
</volume-defaults>

# metassist create -s myset -S 10Gb
 

This example shows how to use the metassist command to create a 10GB stripe, using exactly four slices and an interlace value of 512KB, as specified in the /etc/default/metassist.xml file.