Automatic Suspend and Resume of LDT Operations Due to Insufficient Disk Space

LDT requires adequate storage space headroom to perform LDT operations such as rekeying on GuardPoints. On Linux, if available storage space drops below the threshold required for LDT operations to continue, the LDT operations are automatically suspended. On Windows, LDT will be suspended if there is less than 3 GB free space in the GuardPoint. Once additional storage space is available in the file system, LDT operations automatically resume.

As available space approaches the threshold for automatic suspension, LDT sends an alert to the CipherTrust Manager to notify you that you should free up more storage space before LDT operations are suspended. The alert on the CipherTrust Manager is:

Low space on guard point [GuardPoint], increase free space or LDT will be suspended.

Behavior of Automatic Suspend and Resume of LDT Operations on ext4 File Systems

By default, ext4 file systems reserve a portion of the storage space for use only by privileged processes to prevent running out of storage space in file systems. In this situation, non-privileged processes are automatically blocked from writing to the file system until the free disk space level reaches the minimum threshold. As LDT operates in privileged mode, LDT operations continue without blockage even if the free disk space threshold is low. Because of this ext4 feature, LDT operations on ext4 file systems may not be suspended due to low available storage space, even when the df command reports storage is 100% allocated.