1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
(network-increase-bandwidth)=
# How to increase the network bandwidth
You can increase the network bandwidth of your LXD setup by configuring the transmit queue length (`txqueuelen`).
This change makes sense in the following scenarios:
- You have a NIC with 1 GbE or higher on a LXD host with a lot of local activity (instance-instance connections or host-instance connections).
- You have an internet connection with 1 GbE or higher on your LXD host.
The more instances you use, the more you can benefit from this tweak.
```{note}
The following instructions use a `txqueuelen` value of 10000, which is commonly used with 10GbE NICs, and a `net.core.netdev_max_backlog` value of 182757.
Depending on your network, you might need to use different values.
In general, you should use small `txqueuelen` values with slow devices with a high latency, and high `txqueuelen` values with devices with a low latency.
For the `net.core.netdev_max_backlog` value, a good guideline is to use the minimum value of the `net.ipv4.tcp_mem` configuration.
```
## Increase the network bandwidth on the LXD host
Complete the following steps to increase the network bandwidth on the LXD host:
1. Increase the transmit queue length (`txqueuelen`) of both the real NIC and the LXD NIC (for example, `lxdbr0`).
You can do this temporarily for testing with the following command:
ifconfig <interface> txqueuelen 10000
To make the change permanent, add the following command to your interface configuration in `/etc/network/interfaces`:
up ip link set eth0 txqueuelen 10000
1. Increase the receive queue length (`net.core.netdev_max_backlog`).
You can do this temporarily for testing with the following command:
echo 182757 > /proc/sys/net/core/netdev_max_backlog
To make the change permanent, add the following configuration to `/etc/sysctl.conf`:
net.core.netdev_max_backlog = 182757
## Increase the transmit queue length on the instances
You must also change the `txqueuelen` value for all Ethernet interfaces in your instances.
To do this, use one of the following methods:
- Apply the same changes as described above for the LXD host.
- Set the `queue.tx.length` device option on the instance profile or configuration.
|
