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authorAndy Gospodarek <andy@greyhouse.net>2010-06-02 04:40:18 -0400
committerDavid S. Miller <davem@davemloft.net>2010-06-05 05:23:17 -0400
commitbb1d912323d5dd50e1079e389f4e964be14f0ae3 (patch)
tree7d20fff2e63bc6add251a56625110257d3ccc45f /Documentation/networking
parentebd8e4977a87cb81d93c62a9bff0102a9713722f (diff)
bonding: allow user-controlled output slave selection
v2: changed bonding module version, modified to apply on top of changes from previous patch in series, and updated documentation to elaborate on multiqueue awareness that now exists in bonding driver. This patch give the user the ability to control the output slave for round-robin and active-backup bonding. Similar functionality was discussed in the past, but Jay Vosburgh indicated he would rather see a feature like this added to existing modes rather than creating a completely new mode. Jay's thoughts as well as Neil's input surrounding some of the issues with the first implementation pushed us toward a design that relied on the queue_mapping rather than skb marks. Round-robin and active-backup modes were chosen as the first users of this slave selection as they seemed like the most logical choices when considering a multi-switch environment. Round-robin mode works without any modification, but active-backup does require inclusion of the first patch in this series and setting the 'all_slaves_active' flag. This will allow reception of unicast traffic on any of the backup interfaces. This was tested with IPv4-based filters as well as VLAN-based filters with good results. More information as well as a configuration example is available in the patch to Documentation/networking/bonding.txt. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/bonding.txt84
1 files changed, 82 insertions, 2 deletions
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 61f516b135b4..d0914781830e 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -49,6 +49,7 @@ Table of Contents
493.3 Configuring Bonding Manually with Ifenslave 493.3 Configuring Bonding Manually with Ifenslave
503.3.1 Configuring Multiple Bonds Manually 503.3.1 Configuring Multiple Bonds Manually
513.4 Configuring Bonding Manually via Sysfs 513.4 Configuring Bonding Manually via Sysfs
523.5 Overriding Configuration for Special Cases
52 53
534. Querying Bonding Configuration 544. Querying Bonding Configuration
544.1 Bonding Configuration 554.1 Bonding Configuration
@@ -1318,8 +1319,87 @@ echo 2000 > /sys/class/net/bond1/bonding/arp_interval
1318echo +eth2 > /sys/class/net/bond1/bonding/slaves 1319echo +eth2 > /sys/class/net/bond1/bonding/slaves
1319echo +eth3 > /sys/class/net/bond1/bonding/slaves 1320echo +eth3 > /sys/class/net/bond1/bonding/slaves
1320 1321
1321 13223.5 Overriding Configuration for Special Cases
13224. Querying Bonding Configuration 1323----------------------------------------------
1324When using the bonding driver, the physical port which transmits a frame is
1325typically selected by the bonding driver, and is not relevant to the user or
1326system administrator. The output port is simply selected using the policies of
1327the selected bonding mode. On occasion however, it is helpful to direct certain
1328classes of traffic to certain physical interfaces on output to implement
1329slightly more complex policies. For example, to reach a web server over a
1330bonded interface in which eth0 connects to a private network, while eth1
1331connects via a public network, it may be desirous to bias the bond to send said
1332traffic over eth0 first, using eth1 only as a fall back, while all other traffic
1333can safely be sent over either interface. Such configurations may be achieved
1334using the traffic control utilities inherent in linux.
1335
1336By default the bonding driver is multiqueue aware and 16 queues are created
1337when the driver initializes (see Documentation/networking/multiqueue.txt
1338for details). If more or less queues are desired the module parameter
1339tx_queues can be used to change this value. There is no sysfs parameter
1340available as the allocation is done at module init time.
1341
1342The output of the file /proc/net/bonding/bondX has changed so the output Queue
1343ID is now printed for each slave:
1344
1345Bonding Mode: fault-tolerance (active-backup)
1346Primary Slave: None
1347Currently Active Slave: eth0
1348MII Status: up
1349MII Polling Interval (ms): 0
1350Up Delay (ms): 0
1351Down Delay (ms): 0
1352
1353Slave Interface: eth0
1354MII Status: up
1355Link Failure Count: 0
1356Permanent HW addr: 00:1a:a0:12:8f:cb
1357Slave queue ID: 0
1358
1359Slave Interface: eth1
1360MII Status: up
1361Link Failure Count: 0
1362Permanent HW addr: 00:1a:a0:12:8f:cc
1363Slave queue ID: 2
1364
1365The queue_id for a slave can be set using the command:
1366
1367# echo "eth1:2" > /sys/class/net/bond0/bonding/queue_id
1368
1369Any interface that needs a queue_id set should set it with multiple calls
1370like the one above until proper priorities are set for all interfaces. On
1371distributions that allow configuration via initscripts, multiple 'queue_id'
1372arguments can be added to BONDING_OPTS to set all needed slave queues.
1373
1374These queue id's can be used in conjunction with the tc utility to configure
1375a multiqueue qdisc and filters to bias certain traffic to transmit on certain
1376slave devices. For instance, say we wanted, in the above configuration to
1377force all traffic bound to 192.168.1.100 to use eth1 in the bond as its output
1378device. The following commands would accomplish this:
1379
1380# tc qdisc add dev bond0 handle 1 root multiq
1381
1382# tc filter add dev bond0 protocol ip parent 1: prio 1 u32 match ip dst \
1383 192.168.1.100 action skbedit queue_mapping 2
1384
1385These commands tell the kernel to attach a multiqueue queue discipline to the
1386bond0 interface and filter traffic enqueued to it, such that packets with a dst
1387ip of 192.168.1.100 have their output queue mapping value overwritten to 2.
1388This value is then passed into the driver, causing the normal output path
1389selection policy to be overridden, selecting instead qid 2, which maps to eth1.
1390
1391Note that qid values begin at 1. Qid 0 is reserved to initiate to the driver
1392that normal output policy selection should take place. One benefit to simply
1393leaving the qid for a slave to 0 is the multiqueue awareness in the bonding
1394driver that is now present. This awareness allows tc filters to be placed on
1395slave devices as well as bond devices and the bonding driver will simply act as
1396a pass-through for selecting output queues on the slave device rather than
1397output port selection.
1398
1399This feature first appeared in bonding driver version 3.7.0 and support for
1400output slave selection was limited to round-robin and active-backup modes.
1401
14024 Querying Bonding Configuration
1323================================= 1403=================================
1324 1404
13254.1 Bonding Configuration 14054.1 Bonding Configuration