Debian Addict

Using WireGuard with OSPF and Bird

Wed, 24 Nov 2021 18:18:39 +0000

I’ve long used OpenVPN’s PtP tunnels to set up star-style network topologies across the WAN, with dynamic routing set up using OSPF/Quagga.

WireGuard is new, allows simpler configuration, and is measurably faster than OpenVPN, so naturally I wanted to switch to it.

However, WireGuard seems to be aimed at smaller, simpler use cases, with its AllowedIPs configuration option being used to set up both static routes, as well as a form of allowlist regarding what traffic is allowed to flow through the tunnel. With this, I would have needed to hard code all subnets across the network in each end’s AllowedIPs, which would have prevented taking advantage of routing protocols to dynamically set up routes.

Live increasing a KVM VM's root partition

Sat, 19 Oct 2019 00:52:36 +0000

My mailserver’s root partition has gotten really full lately, and I didn’t want to incur downtime by taking it down to enlarge offline:

root@mail:~# df -hT
Filesystem     Type      Size  Used Avail Use% Mounted on
/dev/vda2      ext4       19G   17G  1.2G  94% /

I run my VMs on KVM and I use an LVM LV for each VM, and according to a SO post, it is possible to increase the size partitions within a VM online, so let’s go for it:

Phanteks p400s Custom Liquid Cooling Loop

Sat, 11 Nov 2017 00:59:55 +0000

I’ve been building computers/servers for roughly 11 years now–first build in 2006 was an Athlon 64 3800+ with a Geforce 6600–and I’ve always only cared about the components themselves, less so what the case or innards look like.

I hit a sort of “midlife crisis” where I wanted to make my home box look really cool. At the time it had 6 hard drives–two mdadm raid1 arrays + 2 SSDs carved using LVM–and I wanted to upgrade to a case with a window, as I was using a windowless Nanoxia Deep Silence 4. The DS4 is a great case but it’s not meant for flashyness. When I built it I hadn’t cared about cable management so it was a mess on the inside.

Fixing Bluetooth audio in Ubuntu Xenial

Sun, 05 Nov 2017 22:50:32 +0000

I have a Sony bluetooth speaker I usually use with iPhone and Macbooks. I’ve wanted to use it with my Ubuntu Xenial (4.4.0-93-generic) desktop for a long time but never got around to getting a bluetooth dongle or an RCA cable.

Today I went to Fry’s to get some cables for another project and finally decided to grab a USB Bluetooth dongle. I picked up a Sabrent BT-UB40 as it claims to have Linux support.

Win7 KVM VGA Passthrough (gtx 750)

Wed, 22 Jul 2015 02:21:15 +0000

I have a Win7 qemu VM passed a gtx 750 and a keyboard+mouse, and the following is a rough guide, inspired from other similar guides which didn’t quite work for me or weren’t informative enough.

Background:

I’m running 64bit Debian Jessie with Qemu/kvm from stock apt. I’m not using libvirt for, as the older version in Debian’s apt does not support -cpu kvm=off among other things. This is a file server/VM host that I choose to use headless, and now it also functions as a very capable gaming rig thanks to virtualization.

Moving from Android to iPhone/iOS

Mon, 18 Aug 2014 07:27:14 +0000

My last iPhone was in 2009, and I switched after around a year when I got sick of AT@T, which used to be the sole carrier for iPhones. Since then I used and loved the Motorola Droid and its Motorola successors. Yesterday, I took the plunge and got an iPhone 5S. Despite the iPhone 6 coming out next month, the feeling of nostalgia was too overbearing to make me want to wait.

Deleting SVN Revisions

Sun, 27 Apr 2014 03:43:55 +0000

Say you have a large SVN repo with 617 commits. You want to physically delete the last 6 so you’re back to r611. You do not want the data contained in these revisions to exist so svn revert is not appropriate.

The most elegant way of killing off r612-r617 is to make a SVN dump up until revision r611 and then restore from it.

Dump the server-side SVN folder and then move it aside:

desktop notifications for irssi nick highlights

Thu, 09 Jan 2014 08:36:49 +0000

I am a long term user of screen+irssi, a quite common way of using IRC for unix-inclined people neckbeards. One problem with this approach is that you will not be notified of events such as nick highlighting and PMs outside of your terminal window.

A quick hack is to use the fnotify irssi script to write highlights to a text file, and then a quick shell one liner to continually read events (lines) from this file and alert you via the gui. This post assumes basic knowledge of irssi, which I’m not going to cover here.

Realtime stats of dd

Tue, 30 Apr 2013 19:51:56 +0000

There are at least two ways of getting the progress of the dd command. One is sending the dd command the -USR1 kill signal, which will cause it to print out its current progress to stderr:

kill -USR1 `pidof dd`

The other way is to examine the fdinfo file (either 0 or 1) for the dd process under /proc to see how much data has currently been copied. This is more efficient and way faster than sending dd a signal as it’s pulling directly from /proc and instead of waiting for dd to catch the signal.

Drastically increase mkfs.ext4 speed

Mon, 01 Apr 2013 14:13:47 +0000

Every now and then, you might want to create an ext4 filesystem on a block device spanning several terabytes, and this is almost always a really long process, taking up to several hours or even days.

There is a little known trick that can significantly reduce the amount of time needed to create ext4 filesystems:

mkfs.ext4 -E lazy_itable_init=1

The lazy_itable_init flag is default on newer versions of e2fsprogs, and the above snippet works on systems as old as Centos5.

su+screen: "Cannot open your terminal '/dev/pts/0' - please check."

Fri, 08 Mar 2013 10:47:46 +0000

Quick tip this time.

Often enough, one is logged in as root and decides to su - to an underprivileged user. Due to the tty for the root shell being owned by the user root, the su’d environment is unable to run screen:

root@whitegirl:~# su - joe joe@whitegirl:~$ screen Cannot open your terminal '/dev/pts/0' - please check. joe@whitegirl:~$

This is resolved by setting the owner of the terminal device to the target user before running su, so the user then has write privileges on the pseudo teletype device:

Diskless Debian Linux booting via dhcp/pxe/nfs/tftp/aufs

Wed, 20 Jun 2012 00:58:12 +0000

Want to boot a (possibly minimal) installation of Debian off the network using a read-only NFS share as the root filesystem, such that each netbooted machine has / mounted read-only over NFS and all writes are done to memory? Read on!

This assumes you are using a Linux computer as your router, which will be running Debian and hosting the local version of Debian we will be serving to clients which are PXE booting. This could be seen as a second part of my tutorial on making a Debian box a router , as it assumes your local network is still 10.0.0.0/24 and the dhcp/nfs/tftp server’s IP is 10.0.0.1

Linux as a router with iptables, bind9, and dhcpd

Wed, 20 Jun 2012 00:10:07 +0000

There are some benefits to using a Linux box as a router. You get full access to the power of iptables, can host stuff directly on the box itself rather than having forwarding ports to other machines on your network, can torrent with way more peers as the box will support more connections than a usual home router, use the router itself as a fileserver/seedbox, etc.

The network setup this entails is as follows: [Modem] - [Linux box/router] - [switch] - [other machines on your network]

Installing php-gtk on Debian

Thu, 15 Sep 2011 05:46:08 +0000

So you want to install PHP’s gtk extension. Compared to GTK’s bindings for Perl and Python, PHP’s apparently is under-maintained and is a pain to install as the developers have not accommodated changes in libtool. We will need to install various development packages, temporarily tweak libtool, and then attempt compiling PHP-GTK and enabling it, provided that didn’t fail.

This tutorial was performed on vanilla 64-bit Debian Squeeze 6.0.2 successfully. Something similar will hopefully work for Ubuntu and other Debian derivatives.

Fixing a dpkg io error

Fri, 19 Aug 2011 03:20:10 +0000

I encountered a dpkg related error a little while ago while upgrading packages on my Ubuntu Lucid server. I couldn’t find a fix on the internet and spent a little while investigating the cause. You can see from the command output that dpkg failed to properly install the Linux kernel package:

root@aeroplane:~# apt-get dist-upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done The following packages will be upgraded: linux-image-2.6.32-33-generic 1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 3 not fully installed or removed. Need to get 0B/31.6MB of archives. After this operation, 0B of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 178303 files and directories currently installed.) Preparing to replace linux-image-2.6.32-33-generic 2.6.32-33.70 (using .../linux-image-2.6.32-33-generic_2.6.32-33.71_i386.deb) ... Done. Unpacking replacement linux-image-2.6.32-33-generic ... dpkg-deb: subprocess paste killed by signal (Broken pipe) dpkg: error processing /var/cache/apt/archives/linux-image-2.6.32-33-generic_2.6.32-33.71_i386.deb (--unpack): short read in buffer_copy (backend dpkg-deb during `./lib/modules/2.6.32-33-generic/kernel/drivers/ata/sata_mv.ko') No apport report written because the error message indicates a dpkg I/O error Running postrm hook script /usr/sbin/update-grub. Generating grub.cfg ... Found initrd image: /boot/initrd.img-2.6.32-33-generic Found linux image: /boot/vmlinuz-2.6.32-32-generic Found initrd image: /boot/initrd.img-2.6.32-32-generic Found linux image: /boot/vmlinuz-2.6.32-31-generic Found initrd image: /boot/initrd.img-2.6.32-31-generic Found linux image: /boot/vmlinuz-2.6.32-30-generic Found initrd image: /boot/initrd.img-2.6.32-30-generic Found linux image: /boot/vmlinuz-2.6.32-29-generic Found initrd image: /boot/initrd.img-2.6.32-29-generic Found linux image: /boot/vmlinuz-2.6.32-28-generic Found initrd image: /boot/initrd.img-2.6.32-28-generic Found linux image: /boot/vmlinuz-2.6.32-27-generic Found initrd image: /boot/initrd.img-2.6.32-27-generic Found linux image: /boot/vmlinuz-2.6.32-26-generic Found initrd image: /boot/initrd.img-2.6.32-26-generic Found linux image: /boot/vmlinuz-2.6.32-25-generic Found initrd image: /boot/initrd.img-2.6.32-25-generic Found linux image: /boot/vmlinuz-2.6.32-24-generic Found initrd image: /boot/initrd.img-2.6.32-24-generic Found linux image: /boot/vmlinuz-2.6.32-21-generic Found initrd image: /boot/initrd.img-2.6.32-21-generic Found memtest86+ image: /boot/memtest86+.bin done Errors were encountered while processing: /var/cache/apt/archives/linux-image-2.6.32-33-generic_2.6.32-33.71_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1) root@aeroplane:~#

Usually ignored features of suPHP

Fri, 19 Aug 2011 02:15:17 +0000

This is not a generic suPHP tutorial as there are many, many of them already; it is merely an attempt to debunk commonly preached misinformation regarding suPHP with cold, hard facts.

suPHP Also works with Lighttpd

suPHP does not just consist of the Apache module mod_suphp; it also consists of a setuid root binary (located at /usr/local/sbin/suphp on FreeBSD; /usr/lib/suphp/suphp on recent Ubuntu releases) which does the actual work. mod_suphp is just an interface to this binary. The binary also works with lighttpd provided you use a configuration file in lighttpd such as the following:

Contact

Fri, 19 Aug 2011 02:10:31 +0000

Joe Gillotti

Contact me on LinkedIn!