bonding: Allow setting max_bonds to zero

[linux-2.6] / Documentation / networking / bonding.txt

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index a0cda062bc33b6e1de3dd2bb60d5ff62bdf97cd4..7fa7fe71d7a8310c00c8cade78688ece2d5250c4 100644 (file)
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -289,35 +289,73 @@ downdelay
 fail_over_mac
 
        Specifies whether active-backup mode should set all slaves to
 fail_over_mac
 
        Specifies whether active-backup mode should set all slaves to

-       the same MAC address (the traditional behavior), or, when
-       enabled, change the bond's MAC address when changing the
-       active interface (i.e., fail over the MAC address itself).
-
-       Fail over MAC is useful for devices that cannot ever alter
-       their MAC address, or for devices that refuse incoming
-       broadcasts with their own source MAC (which interferes with
-       the ARP monitor).
-
-       The down side of fail over MAC is that every device on the
-       network must be updated via gratuitous ARP, vs. just updating
-       a switch or set of switches (which often takes place for any
-       traffic, not just ARP traffic, if the switch snoops incoming
-       traffic to update its tables) for the traditional method.  If
-       the gratuitous ARP is lost, communication may be disrupted.
-
-       When fail over MAC is used in conjuction with the mii monitor,
-       devices which assert link up prior to being able to actually
-       transmit and receive are particularly susecptible to loss of
-       the gratuitous ARP, and an appropriate updelay setting may be
-       required.
-
-       A value of 0 disables fail over MAC, and is the default.  A
-       value of 1 enables fail over MAC.  This option is enabled
-       automatically if the first slave added cannot change its MAC
-       address.  This option may be modified via sysfs only when no
-       slaves are present in the bond.
-
-       This option was added in bonding version 3.2.0.
+       the same MAC address at enslavement (the traditional
+       behavior), or, when enabled, perform special handling of the
+       bond's MAC address in accordance with the selected policy.
+
+       Possible values are:
+
+       none or 0
+
+               This setting disables fail_over_mac, and causes
+               bonding to set all slaves of an active-backup bond to
+               the same MAC address at enslavement time.  This is the
+               default.
+
+       active or 1
+
+               The "active" fail_over_mac policy indicates that the
+               MAC address of the bond should always be the MAC
+               address of the currently active slave.  The MAC
+               address of the slaves is not changed; instead, the MAC
+               address of the bond changes during a failover.
+
+               This policy is useful for devices that cannot ever
+               alter their MAC address, or for devices that refuse
+               incoming broadcasts with their own source MAC (which
+               interferes with the ARP monitor).
+
+               The down side of this policy is that every device on
+               the network must be updated via gratuitous ARP,
+               vs. just updating a switch or set of switches (which
+               often takes place for any traffic, not just ARP
+               traffic, if the switch snoops incoming traffic to
+               update its tables) for the traditional method.  If the
+               gratuitous ARP is lost, communication may be
+               disrupted.
+
+               When this policy is used in conjuction with the mii
+               monitor, devices which assert link up prior to being
+               able to actually transmit and receive are particularly
+               susecptible to loss of the gratuitous ARP, and an
+               appropriate updelay setting may be required.
+
+       follow or 2
+
+               The "follow" fail_over_mac policy causes the MAC
+               address of the bond to be selected normally (normally
+               the MAC address of the first slave added to the bond).
+               However, the second and subsequent slaves are not set
+               to this MAC address while they are in a backup role; a
+               slave is programmed with the bond's MAC address at
+               failover time (and the formerly active slave receives
+               the newly active slave's MAC address).
+
+               This policy is useful for multiport devices that
+               either become confused or incur a performance penalty
+               when multiple ports are programmed with the same MAC
+               address.
+
+
+       The default policy is none, unless the first slave cannot
+       change its MAC address, in which case the active policy is
+       selected by default.
+
+       This option may be modified via sysfs only when no slaves are
+       present in the bond.
+
+       This option was added in bonding version 3.2.0.  The "follow"
+       policy was added in bonding version 3.3.0.

 
 lacp_rate
 
 
 lacp_rate
 


@@ -338,7 +376,8 @@ max_bonds
        Specifies the number of bonding devices to create for this
        instance of the bonding driver.  E.g., if max_bonds is 3, and
        the bonding driver is not already loaded, then bond0, bond1
        Specifies the number of bonding devices to create for this
        instance of the bonding driver.  E.g., if max_bonds is 3, and
        the bonding driver is not already loaded, then bond0, bond1

-       and bond2 will be created.  The default value is 1.
+       and bond2 will be created.  The default value is 1.  Specifying
+       a value of 0 will load bonding, but will not create any devices.

 
 miimon
 
 
 miimon
 


@@ -501,6 +540,17 @@ mode
                swapped with the new curr_active_slave that was
                chosen.
 
                swapped with the new curr_active_slave that was
                chosen.
 

+num_grat_arp
+
+       Specifies the number of gratuitous ARPs to be issued after a
+       failover event.  One gratuitous ARP is issued immediately after
+       the failover, subsequent ARPs are sent at a rate of one per link
+       monitor interval (arp_interval or miimon, whichever is active).
+
+       The valid range is 0 - 255; the default value is 1.  This option
+       affects only the active-backup mode.  This option was added for
+       bonding version 3.3.0.
+

 primary
 
        A string (eth0, eth2, etc) specifying which slave is the
 primary
 
        A string (eth0, eth2, etc) specifying which slave is the