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| author | Jarod Wilson <jarod@redhat.com> | 2021-01-19 04:09:27 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-01-20 06:30:32 +0300 |
| commit | 7b8fc0103bb51d1d3e1fb5fd67958612e709f883 (patch) | |
| tree | a270badd5579c8e8f7c4bfdc98d23a2835fecc4a /Documentation/networking | |
| parent | 00b229f762b020eebf55a52b984aec76ae0ad966 (diff) | |
| download | linux-7b8fc0103bb51d1d3e1fb5fd67958612e709f883.tar.xz | |
bonding: add a vlan+srcmac tx hashing option
This comes from an end-user request, where they're running multiple VMs on
hosts with bonded interfaces connected to some interest switch topologies,
where 802.3ad isn't an option. They're currently running a proprietary
solution that effectively achieves load-balancing of VMs and bandwidth
utilization improvements with a similar form of transmission algorithm.
Basically, each VM has it's own vlan, so it always sends its traffic out
the same interface, unless that interface fails. Traffic gets split
between the interfaces, maintaining a consistent path, with failover still
available if an interface goes down.
Unlike bond_eth_hash(), this hash function is using the full source MAC
address instead of just the last byte, as there are so few components to
the hash, and in the no-vlan case, we would be returning just the last
byte of the source MAC as the hash value. It's entirely possible to have
two NICs in a bond with the same last byte of their MAC, but not the same
MAC, so this adjustment should guarantee distinct hashes in all cases.
This has been rudimetarily tested to provide similar results to the
proprietary solution it is aiming to replace. A patch for iproute2 is also
posted, to properly support the new mode there as well.
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Thomas Davis <tadavis@lbl.gov>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Link: https://lore.kernel.org/r/20210119010927.1191922-1-jarod@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/bonding.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst index adc314639085..5f690f0ad0e4 100644 --- a/Documentation/networking/bonding.rst +++ b/Documentation/networking/bonding.rst @@ -951,6 +951,19 @@ xmit_hash_policy packets will be distributed according to the encapsulated flows. + vlan+srcmac + + This policy uses a very rudimentary vlan ID and source mac + hash to load-balance traffic per-vlan, with failover + should one leg fail. The intended use case is for a bond + shared by multiple virtual machines, all configured to + use their own vlan, to give lacp-like functionality + without requiring lacp-capable switching hardware. + + The formula for the hash is simply + + hash = (vlan ID) XOR (source MAC vendor) XOR (source MAC dev) + 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 |