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A full disk can result in a critical condition for c-treeACE. As the ability to log transactions and write to transaction controlled files is a fundamental necessity, it is important to avoid low disk space conditions. Previously, c-treeACE provided options (DISK_FULL_LIMIT and DISK_FULL_VOLUME) to check for disk space, however, these configurations only made the check after a file extension had completed, and did not provide for a proactive solution. To address this concern with a robust proactive approach, an extended option is available to allow for specified actions to take place when a low disk space condition is detected.
The c-treeACE configuration option DISK_FULL_ACTION enables c-treeACE to monitor available disk space and to shut down the database engine when disk space falls below a specified limit. The usage is:
DISK_FULL_ACTION <action> <volume> <limit>
Currently, the only supported value for <action> is shutdown. This action enables c-treeACE to shut down when the specified disk full limit is reached.
If the path contains spaces, they must be surrounded with double quotes as shown in the following examples:
Windows examples:
DISK_FULL_ACTION shutdown D:\ 500 MB
DISK_FULL_ACTION shutdown "C:\Users\Administrator\My Documents" 1 GB
Unix examples:
DISK_FULL_ACTION shutdown /users/administrator 500 MB
DISK_FULL_ACTION shutdown "/users/administrator/my documents" 1 GB
The keyword can be specified multiple times with actions specified on a per volume basis. DISK_FULL_ACTION is also independent of the DISK_FULL_LIMIT and DISK_FULL_VOLUME keywords. (These older keywords result in disk writes to fail when the limit is reached.)
When this keyword is specified, c-treeACE creates an administrative thread that checks the disk space conditions every 60 seconds. It takes the specified action (currently only shutdown supported) if the limit is reached.
The following new messages appear in CTSTATUS.FCS when this option is used:
1) c-treeACE logs a message for each DISK_FULL_ACTION option it finds in ctsrvr.cfg:
- User# 00001 Configuration info : DISK_FULL_ACTION threshold set for volume S:\ to 7516192768 bytes
2) c-treeACE logs a message to indicate that the available disk space monitoring thread has started:
- User# 00009 Thread Start: ctDISKFULLactionthrd
3) c-treeACE logs a message when it detects disk space below the specified threshold which causes the database engine to shut down:
- User# 00009 DISK_FULL_ACTION: Space on volume S:\ is 5338173440, which is below threshold of 7516192768. Initiating database engine shutdown.
