No Debian, as reinicializações são registradas. De man last
:
Last searches back through the file /var/log/wtmp (or the file desig-
nated by the -f flag) and displays a list of all users logged in (and
out) since that file was created.
...
The pseudo user reboot logs in each time the system is rebooted. Thus
last reboot will show a log of all reboots since the log file was cre-
ated.
O arquivo /var/log/wtmp
já deve estar sob rotação de log por padrão (veja /etc/logrotate.conf
), cuidando disso.
Você pode usar arquivos de log mais antigos usando a opção -f
:
last reboot -f /var/log/wtmp.1