# BSD

* [Desktop](#desktop)
* [TCP congestion control](#tcp-congestion-control)
* [relayd](#relayd)
* [PF](#pf)
  * [ipfw](#ipfw)
* [ZFS](#zfs)
* [DTrace](#dtrace)
* [CAM Target Layer(ctl)](#cam-target-layerctl)
  * [HA cluster](#ha-cluster)

## Desktop

* FreeBSD since 2010, based on FreeBSD
* TrueOS (formerly PC-BSD or PCBSD) ended in 2020

## TCP congestion control

```
sysctl net.inet.tcp.cc
net.inet.tcp.cc.available: newreno
net.inet.tcp.cc.algorithm: newreno

kldload cccubic
kldload ccvegas
kldload cccdg
```

## relayd

<https://man.openbsd.org/relayd.conf.5> layer 3 and/or layer 7 load-balancer, application layer gateway, or transparent proxy

## PF

<https://man.openbsd.org/pf.conf>

```
pass in all 
pass in from any to any 
pass in proto tcp from any port < 1024 to any 
pass in proto tcp from any to any port 25 
pass in proto tcp from 10.0.0.0/8 port >= 1024 \ 
    to ! 10.1.2.3 port != ssh 
pass in proto tcp from any os "OpenBSD" 
pass in proto tcp from route "DTAG" 
```

### ipfw

```
sudo ipfw add fwd 127.0.0.1,12345 tcp from not me to any 80 in via en1
sudo ipfw add fwd 127.0.0.1,12345 tcp from not me to any 443 in via en1
```

## ZFS

<https://www.freebsd.org/cgi/man.cgi?query=zpool>

```
zpool create pool_name da0p3 da1p3
zpool create pool_name \
    mirror da0	da1 \
    mirror da2 da3 \
    log mirror da4 da5
zpool add pool cache	da2 da3

zpool list
zpool get all pool_name
zpool status pool_name
zpool iostat -v pool_name 5
zpool list -v pool_name
```

## DTrace

<https://wiki.freebsd.org/DTrace/Tutorial>

## CAM Target Layer(ctl)

The ctl subsystem provides SCSI target devices emulation

### HA cluster

<https://bsdmag.org/nearly-online-zpool-switching-two-freebsd-machines/>


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