wtmp retention period is very short

[James Troup]

Binary package hint: logrotate

The default log rotation for /var/log/wtmp is that only one rotated
log file is kept. Which means that you can have as little as 31 days
worth of login history available. Considering how small these files
are (~400K on a busy server), is there any good reason not to increase
the default up from 1 to e.g. 12 or 24?

[QkiZ (qkiz)]

You may manually increase time to keep this log files. Edit /etc/logrotate.conf:

...
/var/log/wtmp {
    missingok
    monthly
    create 0664 root utmp
    rotate 1 <------ change this value to 12 to keep log files for 12 months
}
...