NFS clients can maintain use of a file over a halt or reboot (although experiencing a failure to respond during that time), but CIFS, FCP, and iSCSI clients cannot do so safely. Therefore, if the filer is running CIFS, FCP, or iSCSI you may use the -t option to specify the time before shutdown. If halt is invoked without -t, it displays the number of CIFS users, the number of open CIFS files, the number of mapped LUNs and the number of connected FCP and iSCSI clients. Then it prompts you for the number of minutes to delay. cifs terminate automatically notifies all CIFS clients that a CIFS shut-down is scheduled in mins minutes, and asks them to close their open files. CIFS files that are still open at the time the filer halts will lose writes that had been cached but not written. FCP and iSCSI will not notify clients, but will allow administrators to confirm that the mapped LUNs are not in use. LUNs that are in use at the time the filer halts will result in client failures.
reboot logs a message in the /etc/messages file (see messages(5)) file to indicate that the filer was rebooted on purpose.
If you reboot the live filer that has taken over the failed filer, after the reboot, the live filer reinitiates the takeover process.