How to Set the Number of Metadevice Names and Disksets

This procedure describes how to calculate the quantity of metadevice names needed for your configuration, and how to modify the /kernel/drv/md.conf file.

The default number of metadevice names is 128. Many configurations need more than the default. Increasing this number before implementing a configuration saves administration time later.

1. Calculate the quantity of metadevice names needed by determining the largest of the metadevice names to be used in each diskset.

   This requirement is based on the metadevice name value rather than on the actual quantity. For example, if your metadevice names range from d950 to d1000, Solstice DiskSuite software requires 1000 names, not 50.

   The cluster can have a maximum of 8192 metadevice names per diskset.

2. Calculate the total expected number of disksets in the cluster, then add one for private disk management.

   The cluster can have a maximum of 32 disksets.

3. Edit the /kernel/drv/md.conf file.

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   Caution -

   All cluster nodes (or cluster pairs in the cluster-pair topology) must have identical /kernel/drv/md.conf files, regardless of the number of disksets served by each node. Failure to follow this guideline can result in serious Solstice DiskSuite errors and possible loss of data.

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   1. If the calculated quantity of metadevice names exceeds 128, set the nmd field to the largest metadevice name value used in a diskset.

   2. Set the md_nsets field to the quantity calculated in Step 2.

   Changes to the /kernel/drv/md.conf file become operative after a reconfiguration reboot is performed.

Where to Go From Here

To create local replicas, go to "How to Create Metadevice State Database Replicas".