Dell EMC Metro node 7.1 Product Guide

Metadata volumes

Meta-volumes store metro node metadata, including virtual-to-physical mappings, data about devices, virtual volumes, and system configuration settings.

Metadata is stored in cache and backed up on specially designated external volumes called meta-volumes.

After the meta-volume is configured, updates to the metadata are written to both the cache and the meta-volume when the metro node configuration is modified.

Each metro node cluster maintains its own metadata, including:

• The local configuration for the cluster.
• Distributed configuration information shared between clusters.

At system startup, metro node reads the metadata and loads the configuration information onto each director.

When you make changes to the system configuration, metro node writes these changes to the metadata volume.

If metro node loses access to the metadata volume, the metro node directors continue uninterrupted, using the in-memory copy of the configuration. Metro node blocks changes to the system until access is restored or the automatic backup meta-volume is activated.

Meta-volumes experience high I/O only during system startup and upgrade.

I/O activity during normal operations is minimal.