The vRealize Log Insight virtual appliance uses a minimum of 100 GB of storage for incoming logs.
When the volume of logs imported into vRealize Log Insight reaches the storage limit, old log messages are automatically and periodically retired on a first-come-first-retired basis. You can increase the storage limit by adding more storage to the vRealize Log Insight virtual appliance. See Increase the Storage Capacity of the vRealize Log Insight Virtual Appliance.
To preserve old messages, you can enable the archiving feature of vRealize Log Insight. See Data Archiving.
Data stored by vRealize Log Insight is immutable. After a log has been imported, it cannot be removed until it is automatically retired.