What is fstrim? fstrim tells SSDs or thin-provisioned storage which blocks are no longer used by the filesystem so they can be reclaimed. Without TRIM/discard: deleted data still looks “used” to the storage layer SSD performance slowly degrades thin storage pools appear full even when files were deleted write amplification increases (reduces SSD lifespan) Running…
Category: Linux
Debian 13 “trixie” sysctl tutorial
Create or edit a custom config file in /etc/sysctl.d/ sudo nano /etc/sysctl.d/99-custom.conf Add your settings, e.g.: net.ipv4.ip_forward = 1 vm.swappiness = 10 Apply the changes: sudo sysctl –system Verify: sysctl net.ipv4.ip_forward sysctl vm.swappiness
IPv6 RADVD SLAAC Config
# /etc/radvd.conf interface vmbr1 { AdvSendAdvert on; MinRtrAdvInterval 30; MaxRtrAdvInterval 100; prefix 2a0f:85c1:334:8::/64 { AdvAutonomous on; # Enable SLAAC AdvOnLink on; }; };
How do I execute ALL sudo commands without password?
Type the following command as root user: # visudo Append the following entry to run ALL command without a password for a user named tom: tom ALL=(ALL) NOPASSWD:ALL
Wireguard Clients isolation
This will block traffic between clients: ip6tables -I FORWARD -i wg0 -o wg0 -j REJECT –reject-with icmp6-adm-prohibited iptables -I FORWARD -i wg0 -o wg0 -j REJECT –reject-with icmp-admin-prohibited To disable isolation for single client: iptables -I FORWARD -i wg0 -s 10.0.0.3/32 -d 10.0.0.0/24 -j ACCEPT 10.0.0.3/32 – Single client IP 10.0.0.0/24 – Subnet allow to…
Limit proxmox backup disk speed
nano /etc/vzdump.conf add bwlimit: 12207 save This will limit read/write speed to 12 MiB/s during backup
Thermal sensors
for i in /sys/class/thermal/thermal_zone[0-9]/temp /sys/class/hwmon/hwmon[0-9]/temp[0-9]_input /sys/devices/platform/coretemp.[0-9]/hwmon/hwmon[0-9]/temp[0-9]_input do [[ -e $i ]] && echo “$i : $(
Export IP:PORT from random text file to the list
You can use a combination of Linux commands to filter out IP:port pairs from a text file and create a list. Assuming that the IP:port pairs in the file are separated by a space, you can use the grep command to filter out lines that match the IP:port pattern, and then use the cut command…
sysctl.conf
/etc/sysctl.conf net.ipv4.ip_forward=1 net.ipv4.conf.default.rp_filter=0 net.ipv4.conf.all.rp_filter=0 net.ipv6.conf.all.disable_ipv6=1 net.ipv6.conf.default.disable_ipv6=1 net.ipv4.conf.all.proxy_arp=1 sysctl -p
Custom DocumentRoot for a Domain in DirectAdmin
If you need to permanently change Apache DocumentRoot for just a single domain, you should do this as Admin. Go to http://[domain]:2222/CMD_CUSTOM_HTTPD?domain=[domain] In the first window, under Only add the few lines of the VirtualHost you need to insert. Do not add a whole .. Add the following line: |?DOCROOT=/custom/document/root| Don’t forget to put pipes…