IT notes


Convert from RAW to VDI When creating custom “RAW” images using mkimg they can be use in VirtualBox by converting them to “VDI” format, example: $ VBoxManage convertfromraw ec2.raw ec2.vdi --format VDI Converting from raw image file="ec2.raw" to file="ec2.vdi"... Creating dynamic image with size 3221292544 bytes (3073MB)... Once the image is in “VDI” format it can be resized using: $ VBoxManage modifyhd ec2.vdi --resize 8192 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% The above command will resize the image to 8GB.

Raspberry Pi 1 Model B

Raspberry Pi 1 Model B, FreeBSD + wifi cat /var/run/dmesg.boot: KDB: debugger backends: ddb KDB: current backend: ddb Copyright (c) 1992-2016 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD is a registered trademark of The FreeBSD Foundation. FreeBSD 10.3-RELEASE #0 r297264: Fri Mar 25 08:01:14 UTC 2016 [email protected]:/usr/obj/arm.armv6/usr/src/sys/RPI-B arm FreeBSD clang version 3.

uptime 1000 days

uptime >= 1000 days OS: FreeBSD + ZFS + Jails Server: Dell PowerEdge 2900 2xE5420 24GB RAM Colocation: Time to reboot after 4 years: I need to rebuild the RAID and can’t mix SAS drives with SATA on an living array:

L2TP over IPSec

L2TP Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs) or as part of the delivery of services by ISPs. It does not provide any encryption or confidentiality by itself. Rather, it relies on an encryption protocol that it passes within the tunnel to provide privacy. L2TP/IPSec Because of the lack of confidentiality inherent in the L2TP protocol, it is often implemented along with IPsec.

FreeBSD jails

The FreeBSD jail mechanism is an implementation of operating system-level virtualization that allows administrators to partition a FreeBSD-based computer system into several independent mini-systems called jails. Operating-system-level virtualization is a server virtualization method in which the kernel of an operating system allows the existence of multiple isolated user-space instances, instead of just one. Such instances, which are sometimes called containers, software containers, virtualization engines (VEs) or jails (FreeBSD jail or chroot jail), may look and feel like a real server from the point of view of its owners and users.

Port knocking

In computer networking, port knocking is a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports. Once a correct sequence of connection attempts is received, the firewall rules are dynamically modified to allow the host which sent the connection attempts to connect over specific port(s). For example, Using PF on FreeBSD to only open port 22 after X number of attempts to connect on port 1234: