By default, the JUNOS logging utility stops writing messages to a log file when the file reaches 128 KB in size. It closes the file and adds a numerical suffix, then opens and directs messages to a new file with the original name. By default, the logging utility creates up to 10 files before it begins overwriting the contents of the oldest file. The logging utility by default also limits the users who can read log files to the root user and users who have the JUNOS maintenance permission.
To enable all users to read log files, include the world-readable statement at the [edit system syslog archive] hierarchy level. To restore the default permissions, include the no-world-readable statement. You can include the archive statement at the [edit system syslog file filename] hierarchy level to configure the number of files, file size, and permissions for the specified log file. For configuration details, see the information about archiving log files in the JUNOS System Basics Configuration Guide.