Team Exasol
Team Exasol

This article describes the various types of volumes and their properties.

DATA Volume

  • Used to store the persistent data of a database
  • Will be enlarged or shrunk on demand
  • The use of a so-called "Maximum Volume Size" may limit the maximum size of the volume. It is used for clusters that share the disk subsystem across multiple databases.
  • Redundancy usually 2
  • Labels (optional)
  • Allowed Users: Who is allowed to see volume information and is allowed to execute tasks on it (ensure "Allowed Users" are not in the list of "Read-only Users")
  • Volume Type: Data
  • Volume Size (GiB): Shared across all master nodes, multiplied by redundancy

Example: Compressed data 1.5TB (including Indices and Statistics), DATA Volume should be running on 4 master nodes using redundancy 2

Required Disk Space per Node:
(Compressed Data / Quantity of Master Nodes) * Redundancy = Disk Space per Node
-> (1500GiB/4)*2 = 750GiB
  • Nodes List: List of nodes to use in this volume, the standby node must be excluded 
     
  • Number of Master Nodes: Quantity of nodes to hold master segments within the volume, nodes will be taken from the nodes list. 
     
     Must match the amount of active database nodes
  • Block Size (KiB): Leave empty (default 4KiB)
  • Disk: On which storage disk device to run on

 

ARCHIVE Volume

  • Used to store the compressed backups of a database
  • Redundancy usually 2
  • Automatic removal of expired backups if volume is running out of space
  • Cannot be shrunk and needs to be enlarged manually
  • Labels (optional)
  • Allowed Users: Who is allowed to see volume information and is allowed to execute tasks on it (ensure "Allowed Users" are not in the list of "Read-only Users")
  • Volume Type: Archive
  • Volume Size (GiB): Shared across all master nodes, multiplied by redundancy
  • Nodes List: List of nodes to use in this volume, the standby node must be excluded 
     
  • Number of Master Nodes: Quantity of nodes to hold master segments within the volume, nodes will be taken from the nodes list. 
     
     Must match the amount of active database nodes
  • Block Size (KiB): Leave empty (default 64KiB)
    • max. 16 TB for 64 KiB
    • max. 24 TB for 96 KiB
    • max. 32 TB for 128 KiB
    • and so on
  • Disk: On which storage disk device to run on
  • Supported backup restore types:
    • Blocking
    • Non-Blocking
    • Virtual-Access

 

TEMPORARY Volume

  • Used for the temporary tablespace of the database
  • Redundancy 1
  • Will be created automatically during startup of the database
  • Will be removed automatically during shutdown of the database
  • Initial size 1GiB
  • Will be enlarged or shrunk on demand

 

Remote ARCHIVE Volume

  • Used for offline backups of the database
  • Compression may be disabled
  • Supported transfer protocols: FTP, SMB, S3, WebHDFS
  • No mechanism to automatically remove expired backups
  • Supported backup restore types:
    • Blocking