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cf nfo [ enable | disable ] disk_shelf
cf nfo status
The cf command is available only if your filer has the cluster license.
partner giveback incomplete, some data may be lost
forcetakeover [-f] forcetakeover is dangerous and can lead to data corruption; in almost all cases, use cf takeover instead.
Forces one filer to take over its partner even though the filer detects an error that would otherwise prevent a takeover. For example, normally, if a detached or faulty ServerNet cable between the filers causes the filers' NVRAM contents to be unsynchronized, takeover is disabled. However, if you enter the cf forcetakeover command, the filer takes over its partner despite the unsynchronized NVRAM contents. This command might cause the filer being taken over to lose client data. If you use the -f option, the cf command allows such a forcetakeover to proceed without requiring confirmation by the operator.
forcetakeover -d[f] Forces a filer to take over its partner in all cases where a forcetakeover would fail. In addition it will force a takeover even if some partner mailbox disks are inaccessible. It can only be used when cluster_remote is licensed.
forcetakeover -d is very dangerous. Not only can it cause data corruption, if not used carefully, it can also lead to a situation where both the filer and it's partner are operational (split brain). As such, it should only be used as a means of last resort when the takeover and forcetakeover commands are unsuccessful in achieving a takeover. The operator must ensure that the partner filer does not become operational at any time while a filer is in a takeover mode initiated by the use of this command. In conjunction with RAID mirroring, it can allow recovery from a disaster when the two filers in the cluster are located at two distant sites. The use of -f option allows this command to proceed without requiring confirmation by the operator.
If you use the -n option, the cf command allows a takeover to proceed even if the partner node was running an incompatible version of Data ONTAP. The partner node must be cleanly halted in order for this option to succeed. This is used as part of a nondisruptive upgrade process.
nfo [ enable | disable ] disk_shelf
Enables or disables negotiated failover on disk shelf count mismatch.
This command is obsolete. Option cf.takeover.on_disk_shelf_miscompare replaces it.
Negotiated failover is a general facility which supports negotiated failover on the basis of decisions made by various modules. disk_shelf is the only negotiated failover module currently implemented. When communication is first established over the interconnect between the local filer and its partner, a list of disk shelves seen by each node on its A and B loops is exchanged. If a filer sees that the count of shelves that the partner sees on its B loops is greater than the filer's count of shelves on its A loops, the filer concludes that it is ``impaired'' (as it sees fewer of its shelves than its partner does) and asks the partner to take it over. If the partner is not itself impaired, it will accept the takeover request and, in turn, ask the requesting filer to shut down gracefully. The partner takes over after the requesting node shuts down, or after a time-out period of approximately 3 minutes expires. The comparison of disk shelves is only done when communication between the filers is established or re-established (for example, after a node reboots).
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