vif destroy vif_name
vif delete vif_name interface_name
vif add vif_name interface_list
vif { favor | nofavor } interface
vif status [ vif_name ]
vif stat vif_name [ interval ]
In the vif commands, vif_name stands for the name of a virtual interface. The name must be a string that is no longer than 15 characters and meets the following criteria:
Once created, a vif is indistinguishable from a physical network interface. You can inspect and modify statistical and configuration information using the ifconfig and netstat commands, among others.
You can create a vif in one of two modes: multi or single.
Multi-mode vifs are compliant with IEEE 802.3ad (static configuration).In multi-mode, all links are simultaneously active. This mode is only useful if all the links are connected to a switch that supports trunking/aggregation over multiple port connections. The switch must be configured to understand that all the port connections share a common media access control (MAC) address and are part of a single logical interface. The switch is responsible for determining how to forward incoming packets to the filer. The filer supports load balancing on the outgoing network traffic over a multi-mode vif. The user can choose from any of the following three methods:
In single-mode, only one of the links is active at a time. No configuration is neccessary on the switch. If Data ONTAP detects a fault in the active link, an standby link of the vif, if available, is activated. Note that load balancing is not supported on single-mode vifs.
Network interfaces belonging to a vif do not have to be on the same network card. With the vif command, you can also create second-level vifs. For example, a subnetwork has two switches that are capable of trunking over multiple port connections. The filer has a two-link multi-mode vif to one switch and a two-link multi-mode vif to the second switch. You can create a second-level single-mode vif that contains both of the multi-mode vifs. When you configure the second-level vif using the ifconfig command, only one of the two multi-mode vif is brought up as the active link. If all the underlying interfaces in the active vif fail, the second-level vif activates it's standby vif.
You can destroy a virtual interface only if you have configured it down using the ifconfig command.
If all the links in a vif are broken, the vif issues a system log message similar to this:
Fri Oct 16 15:09:29 PDT [toaster: pvif_monitor]: vif0: all links are down
If all links on a vif are broken and a link subsequently comes back up, the vif issues a system log message similar to this:
Fri Oct 16 15:09:42 PDT [toaster: pvif_monitor]: vif0: switching to e3a
vif create multi vif0 -b ip e3a e3b
The status option prints out results in the following form. Here is an example of the output for vif0:
vif status
default: transmit 'IP Load balancing', VIF Type 'multi_mode', fail 'log'
vif0: 2 links, transmit 'none', VIF Type 'multi-mode' fail 'default'
VIF Status Up Addr_set
up:
e10: state up, since 05Oct2001 17:17:15 (05:23:05)
mediatype: auto-1000t-fd-up
flags: enabled
input packets 2000, input bytes 12800
output packets 173, output bytes 1345
up indications 1, broken indications 0
drops (if) 0, drops (link) 0
indication: up at boot
consecutive 3, transitions 1
broken:
e5: state broken, since 05Oct2001 17:18:03 (00:10:03)
mediatype: auto-1000t-fd-down
flags: enabled
input packets 134, input bytes 987
output packets 20, output bytes 156
up indications 1, broken indications 1
drops (if) 0, drops (link) 0
indication: broken
consecutive 4, transitions 1
In this example, one of the vif0 links are is in the active (up) state. The second interface e5 is broken on detection of a link failure. vif0 is configured to transmit over multiple links and its failure behavior is the default (send errors to the system log). Links are in one of three states:
Links constantly issue either up or broken indications based on their interaction with the switch. The consecutive count indicates the number of consecutively received indications with the same value (in this example, up). The transitions count indicates how many times the indication has gone from up to down or from down to up.
If vif0 is a link in a second-layer vif (for example, vif create vif2 vif0), an additional line is added to its status information:
trunked: vif2
vif stat vif0
Virtual interface (trunk) vif0
e10 e5
In Out In Out
8637076 47801540 158 159
1617 9588 0 0
1009 5928 0 0
1269 7506 0 0
1293 7632 0 0
920 5388 0 0
1098 6462 0 0
2212 13176 0 0
1315 7776 0 0
1. The local node must specify, using the partner option of the ifconfig command, the mapping of the partner's virtual interface. For example, to map the partner's vif2 interface to the local vif1 interface, the following command is required:
ifconfig vif1 partner vif2
Note that the interface must be named, not the address. The mapping must be at the top-level trunk, if trunks are nested. You do not map link-by-link.
2. After takeover, the partner must "create" its virtual interface. Typically, this takes place in the /etc/rc file. For example:
vif create vif2 e3a e3b
When executed in takeover mode, the local node does not actually create a vif2 virtual interface. Instead, it looks up the mapping (in this example partner vif2 to local vif1) and initializes its internal data structures. The interface list (in this example, e3a and e3b) is ignored because the local node can have different mappings of devices for its vif1 trunk.
3. After the partner virtual interface has been initialized, it must be configured. For example:
ifconfig vif2 `hostname`-vif2
Only the create, stat, and status options are enabled in partner mode. The create option does not create new vif in partner mode. Instead, it initializes internal data structures to point at the mapped local vif interface. The status and stat options reference the mapped vif . However, all links are printed using the local device names.
When using multi vifs with clusters, connecting the vifs
into a single switch constitutes a single point of failure.
By adding a second switch and setting up two multimode
vifs on each node in the cluster so that the multimode
vifs on each node are connected to separate switches
the vifs will continue to operate in the face of single
switch failure. The following /etc/rc file sequence
illustrates this approach:
# configuration for node 1 # first level multi vif: # attach e4a and e4b to Switch 1 vif create multi vif0 e4a e4b # first level multi vif: # attach e4c and e4d to Switch 2 vif create multi vif1 e4c e4d # second level single vif consisting of both # first level vifs; only one active at a time vif create single vif10 vif0 vif1 # use vif0 unless it is unavailable vif favor vif0 # configure the vif with an interface and partner ifconfig vif10 `hostname-vif10` partner vif10
The partner node is configured similarly; the favored first level interface in this case is the vif connected to "Switch 2".
The fault detection mechanism does not detect whether the switch is connected to the network. A better link fault detection mechanism is prescribed in IEEE 802.3ad ( Dynamic ), but most of the switches do not support this as yet. Link status is the only mechanism used to determine whether a link is up or broken.
The first Gigabit Ethernet interface supported on a filer and indentified with sysconfig command display as the the "Gigabit Ethernet Controller", cannot be configured in a vif. All the later models of Gigabit Ethernet Controllers, supported on the filer, can be configured in a vif.