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diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 5ede7473b42..9c723ecd002 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -1,7 +1,7 @@ Linux Ethernet Bonding Driver HOWTO - Latest update: 12 November 2007 + Latest update: 27 April 2011 Initial release : Thomas Davis <tadavis at lbl.gov> Corrections, HA extensions : 2000/10/03-15 : @@ -49,6 +49,8 @@ Table of Contents 3.3 Configuring Bonding Manually with Ifenslave 3.3.1 Configuring Multiple Bonds Manually 3.4 Configuring Bonding Manually via Sysfs +3.5 Configuration with Interfaces Support +3.6 Overriding Configuration for Special Cases 4. Querying Bonding Configuration 4.1 Bonding Configuration @@ -102,8 +104,7 @@ Table of Contents ============================== Most popular distro kernels ship with the bonding driver -already available as a module and the ifenslave user level control -program installed and ready for use. If your distro does not, or you +already available as a module. If your distro does not, or you have need to compile bonding from source (e.g., configuring and installing a mainline kernel from kernel.org), you'll need to perform the following steps: @@ -122,46 +123,13 @@ device support" section. It is recommended that you configure the driver as module since it is currently the only way to pass parameters to the driver or configure more than one bonding device. - Build and install the new kernel and modules, then continue -below to install ifenslave. + Build and install the new kernel and modules. -1.2 Install ifenslave Control Utility +1.2 Bonding Control Utility ------------------------------------- - The ifenslave user level control program is included in the -kernel source tree, in the file Documentation/networking/ifenslave.c. -It is generally recommended that you use the ifenslave that -corresponds to the kernel that you are using (either from the same -source tree or supplied with the distro), however, ifenslave -executables from older kernels should function (but features newer -than the ifenslave release are not supported). Running an ifenslave -that is newer than the kernel is not supported, and may or may not -work. - - To install ifenslave, do the following: - -# gcc -Wall -O -I/usr/src/linux/include ifenslave.c -o ifenslave -# cp ifenslave /sbin/ifenslave - - If your kernel source is not in "/usr/src/linux," then replace -"/usr/src/linux/include" in the above with the location of your kernel -source include directory. - - You may wish to back up any existing /sbin/ifenslave, or, for -testing or informal use, tag the ifenslave to the kernel version -(e.g., name the ifenslave executable /sbin/ifenslave-2.6.10). - -IMPORTANT NOTE: - - If you omit the "-I" or specify an incorrect directory, you -may end up with an ifenslave that is incompatible with the kernel -you're trying to build it for. Some distros (e.g., Red Hat from 7.1 -onwards) do not have /usr/include/linux symbolically linked to the -default kernel source include directory. - -SECOND IMPORTANT NOTE: - If you plan to configure bonding using sysfs, you do not need -to use ifenslave. + It is recommended to configure bonding via iproute2 (netlink) +or sysfs, the old ifenslave control utility is obsolete. 2. Bonding Driver Options ========================= @@ -171,9 +139,8 @@ bonding module at load time, or are specified via sysfs. Module options may be given as command line arguments to the insmod or modprobe command, but are usually specified in either the -/etc/modules.conf or /etc/modprobe.conf configuration file, or in a -distro-specific configuration file (some of which are detailed in the next -section). +/etc/modrobe.d/*.conf configuration files, or in a distro-specific +configuration file (some of which are detailed in the next section). Details on bonding support for sysfs is provided in the "Configuring Bonding Manually via Sysfs" section, below. @@ -194,6 +161,23 @@ or, for backwards compatibility, the option value. E.g., The parameters are as follows: +active_slave + + Specifies the new active slave for modes that support it + (active-backup, balance-alb and balance-tlb). Possible values + are the name of any currently enslaved interface, or an empty + string. If a name is given, the slave and its link must be up in order + to be selected as the new active slave. If an empty string is + specified, the current active slave is cleared, and a new active + slave is selected automatically. + + Note that this is only available through the sysfs interface. No module + parameter by this name exists. + + The normal value of this option is the name of the currently + active slave, or the empty string if there is no active slave or + the current mode does not use an active slave. + ad_select Specifies the 802.3ad aggregation selection logic to use. The @@ -221,7 +205,7 @@ ad_select - Any slave's 802.3ad association state changes - - The bond's adminstrative state changes to up + - The bond's administrative state changes to up count or 2 @@ -236,6 +220,18 @@ ad_select This option was added in bonding version 3.4.0. +all_slaves_active + + Specifies that duplicate frames (received on inactive ports) should be + dropped (0) or delivered (1). + + Normally, bonding will drop duplicate frames (received on inactive + ports), which is desirable for most users. But there are some times + it is nice to allow duplicate frames to be delivered. + + The default value is 0 (drop duplicate frames received on inactive + ports). + arp_interval Specifies the ARP link monitoring frequency in milliseconds. @@ -274,16 +270,15 @@ arp_ip_target arp_validate Specifies whether or not ARP probes and replies should be - validated in the active-backup mode. This causes the ARP - monitor to examine the incoming ARP requests and replies, and - only consider a slave to be up if it is receiving the - appropriate ARP traffic. + validated in any mode that supports arp monitoring, or whether + non-ARP traffic should be filtered (disregarded) for link + monitoring purposes. Possible values are: none or 0 - No validation is performed. This is the default. + No validation or filtering is performed. active or 1 @@ -297,28 +292,90 @@ arp_validate Validation is performed for all slaves. - For the active slave, the validation checks ARP replies to - confirm that they were generated by an arp_ip_target. Since - backup slaves do not typically receive these replies, the - validation performed for backup slaves is on the ARP request - sent out via the active slave. It is possible that some - switch or network configurations may result in situations - wherein the backup slaves do not receive the ARP requests; in - such a situation, validation of backup slaves must be - disabled. - - This option is useful in network configurations in which - multiple bonding hosts are concurrently issuing ARPs to one or - more targets beyond a common switch. Should the link between - the switch and target fail (but not the switch itself), the - probe traffic generated by the multiple bonding instances will - fool the standard ARP monitor into considering the links as - still up. Use of the arp_validate option can resolve this, as - the ARP monitor will only consider ARP requests and replies - associated with its own instance of bonding. + filter or 4 + + Filtering is applied to all slaves. No validation is + performed. + + filter_active or 5 + + Filtering is applied to all slaves, validation is performed + only for the active slave. + + filter_backup or 6 + + Filtering is applied to all slaves, validation is performed + only for backup slaves. + + Validation: + + Enabling validation causes the ARP monitor to examine the incoming + ARP requests and replies, and only consider a slave to be up if it + is receiving the appropriate ARP traffic. + + For an active slave, the validation checks ARP replies to confirm + that they were generated by an arp_ip_target. Since backup slaves + do not typically receive these replies, the validation performed + for backup slaves is on the broadcast ARP request sent out via the + active slave. It is possible that some switch or network + configurations may result in situations wherein the backup slaves + do not receive the ARP requests; in such a situation, validation + of backup slaves must be disabled. + + The validation of ARP requests on backup slaves is mainly helping + bonding to decide which slaves are more likely to work in case of + the active slave failure, it doesn't really guarantee that the + backup slave will work if it's selected as the next active slave. + + Validation is useful in network configurations in which multiple + bonding hosts are concurrently issuing ARPs to one or more targets + beyond a common switch. Should the link between the switch and + target fail (but not the switch itself), the probe traffic + generated by the multiple bonding instances will fool the standard + ARP monitor into considering the links as still up. Use of + validation can resolve this, as the ARP monitor will only consider + ARP requests and replies associated with its own instance of + bonding. + + Filtering: + + Enabling filtering causes the ARP monitor to only use incoming ARP + packets for link availability purposes. Arriving packets that are + not ARPs are delivered normally, but do not count when determining + if a slave is available. + + Filtering operates by only considering the reception of ARP + packets (any ARP packet, regardless of source or destination) when + determining if a slave has received traffic for link availability + purposes. + + Filtering is useful in network configurations in which significant + levels of third party broadcast traffic would fool the standard + ARP monitor into considering the links as still up. Use of + filtering can resolve this, as only ARP traffic is considered for + link availability purposes. This option was added in bonding version 3.1.0. +arp_all_targets + + Specifies the quantity of arp_ip_targets that must be reachable + in order for the ARP monitor to consider a slave as being up. + This option affects only active-backup mode for slaves with + arp_validation enabled. + + Possible values are: + + any or 0 + + consider the slave up only when any of the arp_ip_targets + is reachable + + all or 1 + + consider the slave up only when all of the arp_ip_targets + are reachable + downdelay Specifies the time, in milliseconds, to wait before disabling @@ -366,10 +423,10 @@ fail_over_mac gratuitous ARP is lost, communication may be disrupted. - When this policy is used in conjuction with the mii + When this policy is used in conjunction 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 + susceptible to loss of the gratuitous ARP, and an appropriate updelay setting may be required. follow or 2 @@ -431,6 +488,23 @@ miimon determined. See the High Availability section for additional information. The default value is 0. +min_links + + Specifies the minimum number of links that must be active before + asserting carrier. It is similar to the Cisco EtherChannel min-links + feature. This allows setting the minimum number of member ports that + must be up (link-up state) before marking the bond device as up + (carrier on). This is useful for situations where higher level services + such as clustering want to ensure a minimum number of low bandwidth + links are active before switchover. This option only affect 802.3ad + mode. + + The default value is 0. This will cause carrier to be asserted (for + 802.3ad mode) whenever there is an active aggregator, regardless of the + number of available links in that aggregator. Note that, because an + aggregator cannot be active without at least one available link, + setting this option to 0 or to 1 has the exact same effect. + mode Specifies one of the bonding policies. The default is @@ -511,13 +585,19 @@ mode balance-tlb or 5 Adaptive transmit load balancing: channel bonding that - does not require any special switch support. The - outgoing traffic is distributed according to the - current load (computed relative to the speed) on each - slave. Incoming traffic is received by the current - slave. If the receiving slave fails, another slave - takes over the MAC address of the failed receiving - slave. + does not require any special switch support. + + In tlb_dynamic_lb=1 mode; the outgoing traffic is + distributed according to the current load (computed + relative to the speed) on each slave. + + In tlb_dynamic_lb=0 mode; the load balancing based on + current load is disabled and the load is distributed + only using the hash distribution. + + Incoming traffic is received by the current slave. + If the receiving slave fails, another slave takes over + the MAC address of the failed receiving slave. Prerequisite: @@ -583,25 +663,32 @@ mode chosen. num_grat_arp +num_unsol_na - 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). + Specify the number of peer notifications (gratuitous ARPs and + unsolicited IPv6 Neighbor Advertisements) to be issued after a + failover event. As soon as the link is up on the new slave + (possibly immediately) a peer notification is sent on the + bonding device and each VLAN sub-device. This is repeated at + each link monitor interval (arp_interval or miimon, whichever + is active) if the number is greater than 1. - 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. + The valid range is 0 - 255; the default value is 1. These options + affect only the active-backup mode. These options were added for + bonding versions 3.3.0 and 3.4.0 respectively. -num_unsol_na + From Linux 3.0 and bonding version 3.7.1, these notifications + are generated by the ipv4 and ipv6 code and the numbers of + repetitions cannot be set independently. + +packets_per_slave - Specifies the number of unsolicited IPv6 Neighbor Advertisements - to be issued after a failover event. One unsolicited NA is issued - immediately after the failover. + Specify the number of packets to transmit through a slave before + moving to the next one. When set to 0 then a slave is chosen at + random. - 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 3.4.0. + The valid range is 0 - 65535; the default value is 1. This option + has effect only in balance-rr mode. primary @@ -612,7 +699,70 @@ primary one slave is preferred over another, e.g., when one slave has higher throughput than another. - The primary option is only valid for active-backup mode. + The primary option is only valid for active-backup(1), + balance-tlb (5) and balance-alb (6) mode. + +primary_reselect + + Specifies the reselection policy for the primary slave. This + affects how the primary slave is chosen to become the active slave + when failure of the active slave or recovery of the primary slave + occurs. This option is designed to prevent flip-flopping between + the primary slave and other slaves. Possible values are: + + always or 0 (default) + + The primary slave becomes the active slave whenever it + comes back up. + + better or 1 + + The primary slave becomes the active slave when it comes + back up, if the speed and duplex of the primary slave is + better than the speed and duplex of the current active + slave. + + failure or 2 + + The primary slave becomes the active slave only if the + current active slave fails and the primary slave is up. + + The primary_reselect setting is ignored in two cases: + + If no slaves are active, the first slave to recover is + made the active slave. + + When initially enslaved, the primary slave is always made + the active slave. + + Changing the primary_reselect policy via sysfs will cause an + immediate selection of the best active slave according to the new + policy. This may or may not result in a change of the active + slave, depending upon the circumstances. + + This option was added for bonding version 3.6.0. + +tlb_dynamic_lb + + Specifies if dynamic shuffling of flows is enabled in tlb + mode. The value has no effect on any other modes. + + The default behavior of tlb mode is to shuffle active flows across + slaves based on the load in that interval. This gives nice lb + characteristics but can cause packet reordering. If re-ordering is + a concern use this variable to disable flow shuffling and rely on + load balancing provided solely by the hash distribution. + xmit-hash-policy can be used to select the appropriate hashing for + the setup. + + The sysfs entry can be used to change the setting per bond device + and the initial value is derived from the module parameter. The + sysfs entry is allowed to be changed only if the bond device is + down. + + The default value is "1" that enables flow shuffling while value "0" + disables it. This option was added in bonding driver 3.7.1 + updelay @@ -647,7 +797,7 @@ use_carrier xmit_hash_policy Selects the transmit hash policy to use for slave selection in - balance-xor and 802.3ad modes. Possible values are: + balance-xor, 802.3ad, and tlb modes. Possible values are: layer2 @@ -669,9 +819,14 @@ xmit_hash_policy Uses XOR of hardware MAC addresses and IP addresses to generate the hash. The formula is - (((source IP XOR dest IP) AND 0xffff) XOR - ( source MAC XOR destination MAC )) - modulo slave count + hash = source MAC XOR destination MAC + hash = hash XOR source IP XOR destination IP + hash = hash XOR (hash RSHIFT 16) + hash = hash XOR (hash RSHIFT 8) + And then hash is reduced modulo slave count. + + If the protocol is IPv6 then the source and destination + addresses are first hashed using ipv6_addr_hash. This algorithm will place all traffic to a particular network peer on the same slave. For non-IP traffic, @@ -695,20 +850,21 @@ xmit_hash_policy The formula for unfragmented TCP and UDP packets is - ((source port XOR dest port) XOR - ((source IP XOR dest IP) AND 0xffff) - modulo slave count + hash = source port, destination port (as in the header) + hash = hash XOR source IP XOR destination IP + hash = hash XOR (hash RSHIFT 16) + hash = hash XOR (hash RSHIFT 8) + And then hash is reduced modulo slave count. + + If the protocol is IPv6 then the source and destination + addresses are first hashed using ipv6_addr_hash. - For fragmented TCP or UDP packets and all other IP - protocol traffic, the source and destination port + For fragmented TCP or UDP packets and all other IPv4 and + IPv6 protocol traffic, the source and destination port information is omitted. For non-IP traffic, the formula is the same as for the layer2 transmit hash policy. - This policy is intended to mimic the behavior of - certain switches, notably Cisco switches with PFC2 as - well as some Foundry and IBM products. - This algorithm is not fully 802.3ad compliant. A single TCP or UDP conversation containing both fragmented and unfragmented packets will see packets @@ -719,33 +875,82 @@ xmit_hash_policy conversations. Other implementations of 802.3ad may or may not tolerate this noncompliance. + encap2+3 + + This policy uses the same formula as layer2+3 but it + relies on skb_flow_dissect to obtain the header fields + which might result in the use of inner headers if an + encapsulation protocol is used. For example this will + improve the performance for tunnel users because the + packets will be distributed according to the encapsulated + flows. + + encap3+4 + + This policy uses the same formula as layer3+4 but it + relies on skb_flow_dissect to obtain the header fields + which might result in the use of inner headers if an + encapsulation protocol is used. For example this will + improve the performance for tunnel users because the + packets will be distributed according to the encapsulated + flows. + The default value is layer2. This option was added in bonding version 2.6.3. In earlier versions of bonding, this parameter does not exist, and the layer2 policy is the only policy. The layer2+3 value was added for bonding version 3.2.2. +resend_igmp + + Specifies the number of IGMP membership reports to be issued after + a failover event. One membership report is issued immediately after + the failover, subsequent packets are sent in each 200ms interval. + + The valid range is 0 - 255; the default value is 1. A value of 0 + prevents the IGMP membership report from being issued in response + to the failover event. + + This option is useful for bonding modes balance-rr (0), active-backup + (1), balance-tlb (5) and balance-alb (6), in which a failover can + switch the IGMP traffic from one slave to another. Therefore a fresh + IGMP report must be issued to cause the switch to forward the incoming + IGMP traffic over the newly selected slave. + + This option was added for bonding version 3.7.0. + +lp_interval + + Specifies the number of seconds between instances where the bonding + driver sends learning packets to each slaves peer switch. + + The valid range is 1 - 0x7fffffff; the default value is 1. This Option + has effect only in balance-tlb and balance-alb modes. 3. Configuring Bonding Devices ============================== You can configure bonding using either your distro's network -initialization scripts, or manually using either ifenslave or the -sysfs interface. Distros generally use one of two packages for the -network initialization scripts: initscripts or sysconfig. Recent -versions of these packages have support for bonding, while older +initialization scripts, or manually using either iproute2 or the +sysfs interface. Distros generally use one of three packages for the +network initialization scripts: initscripts, sysconfig or interfaces. +Recent versions of these packages have support for bonding, while older versions do not. We will first describe the options for configuring bonding for -distros using versions of initscripts and sysconfig with full or -partial support for bonding, then provide information on enabling +distros using versions of initscripts, sysconfig and interfaces with full +or partial support for bonding, then provide information on enabling bonding without support from the network initialization scripts (i.e., older versions of initscripts or sysconfig). - If you're unsure whether your distro uses sysconfig or -initscripts, or don't know if it's new enough, have no fear. + If you're unsure whether your distro uses sysconfig, +initscripts or interfaces, or don't know if it's new enough, have no fear. Determining this is fairly straightforward. - First, issue the command: + First, look for a file called interfaces in /etc/network directory. +If this file is present in your system, then your system use interfaces. See +Configuration with Interfaces Support. + + Else, issue the command: $ rpm -qf /sbin/ifup @@ -914,7 +1119,7 @@ ifcfg-bondX files. Because the sysconfig scripts supply the bonding module options in the ifcfg-bondX file, it is not necessary to add them to -the system /etc/modules.conf or /etc/modprobe.conf configuration file. +the system /etc/modules.d/*.conf configuration files. 3.2 Configuration with Initscripts Support ------------------------------------------ @@ -991,15 +1196,13 @@ queried targets, e.g., arp_ip_target=+192.168.1.1 arp_ip_target=+192.168.1.2 is the proper syntax to specify multiple targets. When specifying -options via BONDING_OPTS, it is not necessary to edit /etc/modules.conf or -/etc/modprobe.conf. +options via BONDING_OPTS, it is not necessary to edit /etc/modprobe.d/*.conf. For even older versions of initscripts that do not support -BONDING_OPTS, it is necessary to edit /etc/modules.conf (or -/etc/modprobe.conf, depending upon your distro) to load the bonding module -with your desired options when the bond0 interface is brought up. The -following lines in /etc/modules.conf (or modprobe.conf) will load the -bonding module, and select its options: +BONDING_OPTS, it is necessary to edit /etc/modprobe.d/*.conf, depending upon +your distro) to load the bonding module with your desired options when the +bond0 interface is brought up. The following lines in /etc/modprobe.d/*.conf +will load the bonding module, and select its options: alias bond0 bonding options bond0 mode=balance-alb miimon=100 @@ -1036,7 +1239,7 @@ not support this method for specifying multiple bonding interfaces; for those instances, see the "Configuring Multiple Bonds Manually" section, below. -3.3 Configuring Bonding Manually with Ifenslave +3.3 Configuring Bonding Manually with iproute2 ----------------------------------------------- This section applies to distros whose network initialization @@ -1045,9 +1248,9 @@ knowledge of bonding. One such distro is SuSE Linux Enterprise Server version 8. The general method for these systems is to place the bonding -module parameters into /etc/modules.conf or /etc/modprobe.conf (as +module parameters into a config file in /etc/modprobe.d/ (as appropriate for the installed distro), then add modprobe and/or -ifenslave commands to the system's global init script. The name of +`ip link` commands to the system's global init script. The name of the global init script differs; for sysconfig, it is /etc/init.d/boot.local and for initscripts it is /etc/rc.d/rc.local. @@ -1059,8 +1262,8 @@ reboots, edit the appropriate file (/etc/init.d/boot.local or modprobe bonding mode=balance-alb miimon=100 modprobe e100 ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up -ifenslave bond0 eth0 -ifenslave bond0 eth1 +ip link set eth0 master bond0 +ip link set eth1 master bond0 Replace the example bonding module parameters and bond0 network configuration (IP address, netmask, etc) with the appropriate @@ -1106,7 +1309,7 @@ options, you may wish to use the "max_bonds" module parameter, documented above. To create multiple bonding devices with differing options, it is -preferrable to use bonding parameters exported by sysfs, documented in the +preferable to use bonding parameters exported by sysfs, documented in the section below. For versions of bonding without sysfs support, the only means to @@ -1121,7 +1324,7 @@ network initialization scripts. specify a different name for each instance (the module loading system requires that every loaded module, even multiple instances of the same module, have a unique name). This is accomplished by supplying multiple -sets of bonding options in /etc/modprobe.conf, for example: +sets of bonding options in /etc/modprobe.d/*.conf, for example: alias bond0 bonding options bond0 -o bond0 mode=balance-rr miimon=100 @@ -1242,11 +1445,17 @@ monitoring is enabled, and vice-versa. To add ARP targets: # echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target # echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target - NOTE: up to 10 target addresses may be specified. + NOTE: up to 16 target addresses may be specified. To remove an ARP target: # echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target +To configure the interval between learning packet transmits: +# echo 12 > /sys/class/net/bond0/bonding/lp_interval + NOTE: the lp_inteval is the number of seconds between instances where +the bonding driver sends learning packets to each slaves peer switch. The +default interval is 1 second. + Example Configuration --------------------- We begin with the same example that is shown in section 3.3, @@ -1278,8 +1487,141 @@ echo 2000 > /sys/class/net/bond1/bonding/arp_interval echo +eth2 > /sys/class/net/bond1/bonding/slaves echo +eth3 > /sys/class/net/bond1/bonding/slaves +3.5 Configuration with Interfaces Support +----------------------------------------- + + This section applies to distros which use /etc/network/interfaces file +to describe network interface configuration, most notably Debian and it's +derivatives. + + The ifup and ifdown commands on Debian don't support bonding out of +the box. The ifenslave-2.6 package should be installed to provide bonding +support. Once installed, this package will provide bond-* options to be used +into /etc/network/interfaces. + + Note that ifenslave-2.6 package will load the bonding module and use +the ifenslave command when appropriate. -4. Querying Bonding Configuration +Example Configurations +---------------------- + +In /etc/network/interfaces, the following stanza will configure bond0, in +active-backup mode, with eth0 and eth1 as slaves. + +auto bond0 +iface bond0 inet dhcp + bond-slaves eth0 eth1 + bond-mode active-backup + bond-miimon 100 + bond-primary eth0 eth1 + +If the above configuration doesn't work, you might have a system using +upstart for system startup. This is most notably true for recent +Ubuntu versions. The following stanza in /etc/network/interfaces will +produce the same result on those systems. + +auto bond0 +iface bond0 inet dhcp + bond-slaves none + bond-mode active-backup + bond-miimon 100 + +auto eth0 +iface eth0 inet manual + bond-master bond0 + bond-primary eth0 eth1 + +auto eth1 +iface eth1 inet manual + bond-master bond0 + bond-primary eth0 eth1 + +For a full list of bond-* supported options in /etc/network/interfaces and some +more advanced examples tailored to you particular distros, see the files in +/usr/share/doc/ifenslave-2.6. + +3.6 Overriding Configuration for Special Cases +---------------------------------------------- + +When using the bonding driver, the physical port which transmits a frame is +typically selected by the bonding driver, and is not relevant to the user or +system administrator. The output port is simply selected using the policies of +the selected bonding mode. On occasion however, it is helpful to direct certain +classes of traffic to certain physical interfaces on output to implement +slightly more complex policies. For example, to reach a web server over a +bonded interface in which eth0 connects to a private network, while eth1 +connects via a public network, it may be desirous to bias the bond to send said +traffic over eth0 first, using eth1 only as a fall back, while all other traffic +can safely be sent over either interface. Such configurations may be achieved +using the traffic control utilities inherent in linux. + +By default the bonding driver is multiqueue aware and 16 queues are created +when the driver initializes (see Documentation/networking/multiqueue.txt +for details). If more or less queues are desired the module parameter +tx_queues can be used to change this value. There is no sysfs parameter +available as the allocation is done at module init time. + +The output of the file /proc/net/bonding/bondX has changed so the output Queue +ID is now printed for each slave: + +Bonding Mode: fault-tolerance (active-backup) +Primary Slave: None +Currently Active Slave: eth0 +MII Status: up +MII Polling Interval (ms): 0 +Up Delay (ms): 0 +Down Delay (ms): 0 + +Slave Interface: eth0 +MII Status: up +Link Failure Count: 0 +Permanent HW addr: 00:1a:a0:12:8f:cb +Slave queue ID: 0 + +Slave Interface: eth1 +MII Status: up +Link Failure Count: 0 +Permanent HW addr: 00:1a:a0:12:8f:cc +Slave queue ID: 2 + +The queue_id for a slave can be set using the command: + +# echo "eth1:2" > /sys/class/net/bond0/bonding/queue_id + +Any interface that needs a queue_id set should set it with multiple calls +like the one above until proper priorities are set for all interfaces. On +distributions that allow configuration via initscripts, multiple 'queue_id' +arguments can be added to BONDING_OPTS to set all needed slave queues. + +These queue id's can be used in conjunction with the tc utility to configure +a multiqueue qdisc and filters to bias certain traffic to transmit on certain +slave devices. For instance, say we wanted, in the above configuration to +force all traffic bound to 192.168.1.100 to use eth1 in the bond as its output +device. The following commands would accomplish this: + +# tc qdisc add dev bond0 handle 1 root multiq + +# tc filter add dev bond0 protocol ip parent 1: prio 1 u32 match ip dst \ + 192.168.1.100 action skbedit queue_mapping 2 + +These commands tell the kernel to attach a multiqueue queue discipline to the +bond0 interface and filter traffic enqueued to it, such that packets with a dst +ip of 192.168.1.100 have their output queue mapping value overwritten to 2. +This value is then passed into the driver, causing the normal output path +selection policy to be overridden, selecting instead qid 2, which maps to eth1. + +Note that qid values begin at 1. Qid 0 is reserved to initiate to the driver +that normal output policy selection should take place. One benefit to simply +leaving the qid for a slave to 0 is the multiqueue awareness in the bonding +driver that is now present. This awareness allows tc filters to be placed on +slave devices as well as bond devices and the bonding driver will simply act as +a pass-through for selecting output queues on the slave device rather than +output port selection. + +This feature first appeared in bonding driver version 3.7.0 and support for +output slave selection was limited to round-robin and active-backup modes. + +4 Querying Bonding Configuration ================================= 4.1 Bonding Configuration @@ -1553,8 +1895,8 @@ route additions may cause trouble. On systems with network configuration scripts that do not associate physical devices directly with network interface names (so that the same physical device always has the same "ethX" name), it may -be necessary to add some special logic to either /etc/modules.conf or -/etc/modprobe.conf (depending upon which is installed on the system). +be necessary to add some special logic to config files in +/etc/modprobe.d/. For example, given a modules.conf containing the following: @@ -1581,20 +1923,15 @@ add above bonding e1000 tg3 bonding is loaded. This command is fully documented in the modules.conf manual page. - On systems utilizing modprobe.conf (or modprobe.conf.local), -an equivalent problem can occur. In this case, the following can be -added to modprobe.conf (or modprobe.conf.local, as appropriate), as -follows (all on one line; it has been split here for clarity): + On systems utilizing modprobe an equivalent problem can occur. +In this case, the following can be added to config files in +/etc/modprobe.d/ as: -install bonding /sbin/modprobe tg3; /sbin/modprobe e1000; - /sbin/modprobe --ignore-install bonding +softdep bonding pre: tg3 e1000 - This will, when loading the bonding module, rather than -performing the normal action, instead execute the provided command. -This command loads the device drivers in the order needed, then calls -modprobe with --ignore-install to cause the normal action to then take -place. Full documentation on this can be found in the modprobe.conf -and modprobe manual pages. + This will load tg3 and e1000 modules before loading the bonding one. +Full documentation on this can be found in the modprobe.d and modprobe +manual pages. 8.3. Painfully Slow Or No Failed Link Detection By Miimon --------------------------------------------------------- @@ -1718,7 +2055,7 @@ access to fail over to. Additionally, the bonding load balance modes support link monitoring of their members, so if individual links fail, the load will be rebalanced across the remaining devices. - See Section 13, "Configuring Bonding for Maximum Throughput" + See Section 12, "Configuring Bonding for Maximum Throughput" for information on configuring bonding with one peer device. 11.2 High Availability in a Multiple Switch Topology @@ -1794,7 +2131,7 @@ target to query. generally referred to as "trunk failover." This is a feature of the switch that causes the link state of a particular switch port to be set down (or up) when the state of another switch port goes down (or up). -It's purpose is to propogate link failures from logically "exterior" ports +Its purpose is to propagate link failures from logically "exterior" ports to the logically "interior" ports that bonding is able to monitor via miimon. Availability and configuration for trunk failover varies by switch, but this can be a viable alternative to the ARP monitor when using @@ -2371,18 +2708,15 @@ enslaved. 16. Resources and Links ======================= -The latest version of the bonding driver can be found in the latest + The latest version of the bonding driver can be found in the latest version of the linux kernel, found on http://kernel.org -The latest version of this document can be found in either the latest -kernel source (named Documentation/networking/bonding.txt), or on the -bonding sourceforge site: - -http://www.sourceforge.net/projects/bonding + The latest version of this document can be found in the latest kernel +source (named Documentation/networking/bonding.txt). -Discussions regarding the bonding driver take place primarily on the -bonding-devel mailing list, hosted at sourceforge.net. If you have -questions or problems, post them to the list. The list address is: + Discussions regarding the usage of the bonding driver take place on the +bonding-devel mailing list, hosted at sourceforge.net. If you have questions or +problems, post them to the list. The list address is: bonding-devel@lists.sourceforge.net @@ -2391,8 +2725,19 @@ be found at: https://lists.sourceforge.net/lists/listinfo/bonding-devel + Discussions regarding the development of the bonding driver take place +on the main Linux network mailing list, hosted at vger.kernel.org. The list +address is: + +netdev@vger.kernel.org + + The administrative interface (to subscribe or unsubscribe) can +be found at: + +http://vger.kernel.org/vger-lists.html#netdev + Donald Becker's Ethernet Drivers and diag programs may be found at : - - http://www.scyld.com/network/ + - http://web.archive.org/web/*/http://www.scyld.com/network/ You will also find a lot of information regarding Ethernet, NWay, MII, etc. at www.scyld.com. |