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@zman0900
zman0900 / unifi-controller-systemd-nspawn.md
Last active January 27, 2024 12:14

Running Unifi Controller in systemd-nspawn with cloud-init

This uses Ubuntu's server cloud image as a stateless container to run the UBNT Unifi Controller software. Configuration data is stored in a directory outside the container. Cloud-init is used to automatically set up the container image, so a new version can be dropped in with minimal effort. This should work with pretty much any modern Linux distro with systemd.

Setup

Systemd-nspawn prefers to store its machines on btrfs, so if your /var/lib/machines is not currently btrfs, you should create one and mount it there. Otherwise it will automatically create an image file at /var/lib/machines.raw and mount it.

Create a device

@sjenning
sjenning / hugepages.md
Last active May 17, 2023 23:52

Linux Hugepages

Hugepages are a hardware feature designed to reduce pressure on the translation lookaside buffer (TLB) for applications that operate on large contiguous memory regions.

Take a program that operates on a large 2MB internal structure as an example. If the program accesses that space in such a way that one byte in each regular 4k page is accessed, 2M/4k = 512 TLB entries are needed. Each TLB miss at the hardware level requires and interrupt and kernel intervention to resolve. However, if the allocation is backed by a 2M hugepage by mmap()ing with MAP_HUGETLB, only 1 TLB entry is required.

On x86_64, there are two hugepage sizes: 2MB and 1G. 1G hugepages are also called gigantic pages. 1G must be enabled on kernel boot line with hugepagesz=1G. Hugeages, especially 1G ones, should to be allocated early before memory fragments (i.e. at/near boot time) to increase the likelihood that they can be allocated successfully with minimal memory migration (i.e. defreg) required

@alq666
alq666 / haproxy-stats
Created May 24, 2016 14:10
HAProxy metrics
0. pxname [LFBS]: proxy name
1. svname [LFBS]: service name (FRONTEND for frontend, BACKEND for backend,
any name for server/listener)
2. qcur [..BS]: current queued requests. For the backend this reports the
number queued without a server assigned.
3. qmax [..BS]: max value of qcur
4. scur [LFBS]: current sessions
5. smax [LFBS]: max sessions
6. slim [LFBS]: configured session limit
7. stot [LFBS]: cumulative number of connections
@julz
julz / main.go
Created November 20, 2015 12:39
containersched minicontainer
package main
import (
"fmt"
"os"
"os/exec"
"syscall"
)
func main() {
@JosephRedfern
JosephRedfern / Speedtest
Last active September 16, 2015 21:35
Scaleway ARM machine
root@beryllium:~# wget http://cachefly.cachefly.net/100mb.test
converted 'http://cachefly.cachefly.net/100mb.test' (ANSI_X3.4-1968) -> 'http://cachefly.cachefly.net/100mb.test' (UTF-8)
--2015-09-03 11:28:49-- http://cachefly.cachefly.net/100mb.test
Resolving cachefly.cachefly.net (cachefly.cachefly.net)... 62.210.187.96
Connecting to cachefly.cachefly.net (cachefly.cachefly.net)|62.210.187.96|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: '100mb.test'
100mb.test 100%[==========================================================================================================================================>] 100.00M 50.1MB/s in 2.0s