This week I needed to backup a Percona MySQL server.One solution for this, is to stop the MySQL server, create a mysqldump, and transfer it to your backup location. However, depending on your tables and data size, this might not be the best solution. Especially if the database you want to backup is a live… Continue reading Streaming MySQL backup
Articles
image-orientation CSS property
The other day I was investigating an issue with Chrome 83 and a MJPEG stream embedded in an <img /> The MJPEG stream was streaming an iPhone screen to the end user. When the user decided to rotate the screen (switching between portrait and landscape), the MJPEG stream was updated accordingly when viewing the stream… Continue reading image-orientation CSS property
WireGuard: an alternative to OpenVPN
This week I’ve been experimenting with WireGuard, which is a relatively new alternative to OpenVPN. It claims to be faster and more secure than other VPN products, partly because its codebase is very small compared to other VPN products. WireGuard is easy to configure. It is compatible with many Linux distro’s, including Ubuntu. For my… Continue reading WireGuard: an alternative to OpenVPN
Speeding up your OpenVPN tunnel
Here are some settings to speed up the transmission rate through your OpenVPN tunnel: proto udp mssfix 0 fragment 0 mssfix: Even though MSS itself is a TCP feature, this OpenVPN option targets encapsulated UDP packets. It will change the MSS value of the TCP protocol inside the tunnel in such a way that after… Continue reading Speeding up your OpenVPN tunnel
A gateway to forward all traffic to a remote VPN server
Suppose you’ve setup a VM and configured it as a site-to-site VPN with OpenVPN, using iroute and staticclients. You are using this VM as a default gateway for other VMs and now want to forward all traffic from the VMs not through the default gateway‘s adapter, but through the VPN tunnel. Why would you want… Continue reading A gateway to forward all traffic to a remote VPN server
VMsvga2
If you’re running macOS with QEMU, you’ll notice that the UI might be slow. This is because, by default, QEMU will use a basic display adapter with low display memory (VRAM). There’s two ways to fix this problem: Pass-through your GPU with vfio Use another display adapter, such as VMsvga2 This post will focus on… Continue reading VMsvga2
Resizing an OSX VM with apfs and QEMU
Looking to resize an existing qcow2 or raw data volume with QEMU? I had to do the same thing and went through some trouble in trying to do this. My first idea was to use GParted and boot from the live-cd iso to extend the apfs partition. However, it turns out that GParted does not… Continue reading Resizing an OSX VM with apfs and QEMU
Hyper-V Enlightenments with Libvirt
With Windows 10, it’s helpful to enable Hyper-V Enlightenments, to save CPU and increase VM responsiveness. To use these enlightenments, edit your libvirt xml: <features> <acpi/> <apic/> <pae/> <hyperv> <relaxed state=’on’/> <vapic state=’on’/> <spinlocks state=’on’ retries=’8191’/> <vpindex state=’on’/> <synic state=’on’/> <stimer state=’on’/> <reset state=’on’/> </hyperv> </features> More information available on https://fossies.org/linux/qemu/docs/hyperv.txt Another interesting note: if… Continue reading Hyper-V Enlightenments with Libvirt
Content Caching on OSX VMs
Apple’s Content Caching is not available when running OSX in a VM. It seems Apple is detecting if it’s running inside a VM: To get around this, you can patch the kernel to remove the cpuid features check: First disable SIP Next: sudo mount -uw / kernel_autopatcher.py /System/Library/Kernels/kernel sudo kextcache -i / Reference: https://github.com/kholia/OSX-KVM/blob/master/reversing-notes.md