List Journal Entries from Boot
- List logs from current boot
- List logs from past boots
List Logs Based on Time
List Logs Based on Service Unit
- Check logs from a single service
- Check interleaved records from multiple units
- Following logs of services
- List last n entries from the logs
- Check existing disk usage
- Delete old logs
- Keep logs persistent
- Limit journal storage
You can set the storage limits in "/etc/systemd/journald.conf" by setting values to the following entries 
- SystemMaxUse=: Specifies the maximum disk space that can be used by the journal in persistent storage.
- SystemKeepFree=: Specifies the amount of space that the journal should leave free when adding journal entries to persistent storage.
- SystemMaxFileSize=: Controls how large individual journal files can grow to in persistent storage before being rotated.
- RuntimeMaxUse=: Specifies the maximum disk space that can be used in volatile storage (within the /run filesystem).
- RuntimeKeepFree=: Specifies the amount of space to be set aside for other uses when writing data to volatile storage (within the /run filesystem). RuntimeMaxFileSize=: Specifies the amount of space that an individual journal file can take up in volatile storage (within the /run filesystem) before being rotated.