Volumes are used to store data in Exasol and are assigned to a storage disk. Refer to Storage Overview for more information on disk layout. You can view the volumes in your Exasol system by going to Services > EXAStorage:
Volume Types and Purposes
There are two types of volumes in Exasol:
- Data volumes
- Archive volumes
A typical Exasol setup contains at least one data volume and an archive volume. When a database instance is started, Exasol creates a temporary data volume for storing temporary database data.
Volumes in Exasol serve three different purposes:
|Volume Purpose||Volume Type||Description|
|Storage of Persistent Data||Data||
For storing the persistent data of a database. These data volumes have the following characteristics:
|Storage of Archive Data||Archive||
For storing compressed backups of a database. Archive volumes have the following characteristics:
|Storage of Temporary Database Data||Data||
For storing the temporary tablespace of a database instance. Temporary volumes have the following characteristics:
When creating a data volume or a local archive volume, you set the number of master nodes the volume will use and assign the master nodes to the volume. Master nodes are the active nodes in a cluster. For example: in a cluster that will have 4 active nodes and 1 reserve node (a '4+1' setup), the number of active nodes, and thus master nodes, is 4.
In the case of data volumes for storing persistent database data, the number of master nodes must match the number of active nodes you set when you create the database.
Manage Volume Capacity
Automatic growth, shrink on demand
Volumes grow automatically as long as enough disk space is available, typically because tables grow due to insert statements. Volumes can be shrunk by clicking the Action shrink on the EXASolution Instance page.
Increase disk space
In order to increase capacity, either new disks can be added to existing nodes or new nodes can be added to the cluster. Refer to the Increase Storage Volume section for more information. In a virtualized environment, existing virtual disks can be enlarged.