I would like to delete following files with newsyslog.conf when the files are older than 6 month:# logfile    [owner:group]    mode    count    size    when    flags    [/pid_file]/mnt/usb/access_*.logWhich other options do I have to set?
newsyslog.conf logrotate when file is older than 6 month
freebsd;backup;syslog;logrotate
You need to specify values for all of the mandatory fields.The following will cause new log files to be created with mode 644, and will keep at most 6 files, before deleting the oldest. The * in the size field tells newsyslog not to consider the size of the file when running. $M1D0 means rotate the file once a month, on the first day of the month, at midnight. GJN tells newsyslog that the filename is a shell pattern and that it should rotate all files that match (G), that it should compress the rotated file with bzip2 (J), and that it does not need to send a signal to a daemon process (N).# logfile    [owner:group]  mode  count  size  when    flags/mnt/usb/access_*.log       644   6      *     $M1D0   GJNWithout knowing more about your use case, it's impossible to give you a more specific instruction. For example, you say nothing about how these files are written, or what ownership should apply, but the newsyslog.conf manpage is pretty detailed, and should help you fill in the blanks.