Disk Requirements
Disk space usage is based on the space used by the core application, the staging directory used for installation, and the space used for the THL files:
- The staging directory containing the core installation is approximately 150MB. This space will be required on each server.
- Each component creates log files within this staging directory. Log rotation should be configured to ensure these files do not grow out of control.
- The THL files required for installation are based on the size of the binary logs generated by MySQL. THL size is typically twice the size of the binary log. This space will be required on each machine in the cluster. The retention times and rotation of THL data can be controlled, see "The thl Directory" for more information, including how to change the retention time and move files during operation.
A dedicated partition for THL and/or Tungsten Software is recommended to ensure that a full disk does not impact your OS or DBMS. Local disk, SAN, iSCSI and AWS EBS are suitable for storing THL. NFS is NOT recommended.
Because the replicator reads and writes information using buffered I/O in a serial fashion, there is no random-access or seeking.
Disk Full issues are generally the biggest cause of failures resulting in support calls. It is strongly advised that sufficient monitoring is put in place to alert on disk space related issues so that they can be remedied before an outage occurs.
A disk full situation would not cause a database failover as this could result in data loss.