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NAME

na_halt - Stops the node.

SYNOPSIS

halt [ -t <mins> ] [ -f ] [ -s ]
halt [ -d <dump_string> ]

DESCRIPTION

halt shuts the node down. The halt command has two forms. The first form flushes all data to disk, and performs a clean shutdown. The second form dumps system core without flushing cached data.

NFS clients can maintain use of a file over a halt or reboot, although the node will fail to respond during that time. CIFS, FCP, and iSCSI clients cannot safely maintain use of a file over a halt or reboot. If the node 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 node 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 node halts will result in client failures.

halt logs a message in /etc/messages to indicate that the node was halted on purpose.

OPTION

-t mins Initiates a clean system shutdown after the indicated number of minutes. Applies only if the node is running CIFS, FCP or iSCSI.

-f
Applies only to nodes in a High Availability (HA) configuration. If you enter the halt -f command on a node, its partner does not take over.

-s
Performs a clean system shutdown. The behavior of this command is different across releases. In Data ONTAP releases prior to 8.0.4 and 8.1.2 the end result of this command is to power off the controller. The user has to power on the controller using the RLM or SP. In Data ONTAP releases 8.0.4, 8.1.2 and beyond, it will no longer power off the controller. Instead, it will halt at the LOADER prompt. For platforms that have FRU attention LEDs on the motherboard, Data ONTAP will clear these LEDs when subsequently booted. This applies only to Data ONTAP 8.0 and later.

-d dump_string
Dumps system core and halts the node. This results in a dirty shutdown; cached data will not be flushed to disk. The dump_string should indicate the reason for the core dump. Because it results in a dirty shutdown, the -d option generally should not be used for normal maintenance (see NOTES below).

HA CONSIDERATIONS

After you enter the halt command on a node in a HA configuration, the other node in the HA configuration automatically takes over the halted node. If you do not want takeover to happen, use the halt -f command.

The halt command is not available in partner mode. That is, you cannot enter the partner halt command on the live node after it takes over the failed partner. This is because a node that has been taken over is no longer running and cannot be halted.

NOTES

To shut down the node for maintenance, use the first form of halt, since it does a clean shutdown. That is, halt [ -t <mins> ] [ -f ].

When the -d option is used, cached data is not flushed to disk. All data not yet on disk is stored in the NVRAM. The node will automatically replay NVRAM during the next boot, bringing the disks up to date with the most recent operation. However, if NVRAM loses charge, some of the most recently modified data may be lost. Because of this, the -d option should be used only to produce coredumps requested by technical support. NVRAM retains charge for three days, so all data will be intact if NVRAM is replayed within three days of the dirty shutdown.

SEE ALSO

na_cifs_terminate(1), na_partner(1), na_reboot(1), na_savecore(1), na_messages(5)


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