Managing Storage Groups

A storage group is a logical storage unit that can be associated with one or more archives in your database. A storage group is said to be online if there are one or more running SMs that serve the storage group. A storage group is said to be offline if no running SMs serve that storage group.

A storage group that has been online and then went offline cannot be brought back online with the database contains running TEs.

Using the get storage-groups command, you can display information about storage groups in your domain.

Storage groups are associated with archives using the add storage-group command. If the storage group specified in the command does not exist in the database, it will be created. See Adding a Storage Group to an Archive for more details.

Storage group associations are removed from archives using the remove storage-group command. Removing a storage group results in the archive no longer storing data for that storage group. You cannot remove all archives associated with a storage group if the storage group has table partitions with data in them. See Removing a Storage Group from an Archive for more details.

A storage group goes permanently offline for two reasons:

  • The storage group is removed from all archives with no intent of adding it back to any archive.

  • All archives serving the storage group are damaged or lost.

Permanently offline storage groups must be deleted from the database using the delete storage-group command. See Deleting a Storage Group from a Database for more details.

get storage-groups, add storage-group, remove storage-group and delete storage-group are issued using NuoDB Command (nuocmd). For more information on NuoDB Command and other command line tools, see Command Line Tools.