How to Dynamically Switch Between Uniprocessor and SMP during Windows XP boot

If you're running Windows XP inside a Virtual Machine such as VirtualBox, Vmware or KVM, you may want to sometimes boot with only one active CPU, other times with several CPUs. If you don't set up windows correctly, it will neither boot normally, nor in safe mode (where it will stop with a blank screen and a blinking cursor).

But you can edit your boot.ini to look like this in order to dynamically switch between one and several processors in Windows XP:
[boot loader]
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro" /noexecute=optin /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro one processor" /noexecute=optin /fastdetect /kernel=ntoskrnl.exe /HAL=Halaacpi.dll
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Pro SMP" /noexecute=optin /fastdetect /kernel=ntkrnlmp.exe /hal=halmacpi.dll

The Ultimate Setup Guide for ownCloud on Small Systems such as the Raspberry Pi

It took me about a year to collect this information. There are many guides, but all I found are incomplete. Here's the one guide to rule them all - hopefully. The guide works on Ubuntu and Debian without changes. It's optimized for resources, speed, security and ease of use. While this runs well on my old phone (ARMv7; 512 MB; ~1000 BogoMIPS), it should run even better on a Raspberry Pi.

Accessing Public ownCloud shares via WebDAV

Since ownCloud supports server to server sharing you can access public shares via webdav clients. You simply use the access token (t=...) as user name. If there is a password, use that as password, otherwise leave it blank. As URL you use the owncloud address with /public.php/webdav at the end:

-> webdavs://

Speeding up your ownCloud on small systems such as the Raspberry Pi with Sqlite

I had seriously considered to use a raspberry pi system for setting up my ownCloud server. But the old pi had pretty much the same capabilities as my old mobile phone with cyanogen. And the phone has Wifi and some flash space already included. So I opted for the phone. As with most pi installations, the performance was not great. But I found some easy tweaks I haven't seen anywhere else to significantly improve the performance. I'm assuming you're already using the usual tweaks such as opcache(this will usually help more than the following tweaks!) and using cron.php. Please backup your owncloud.db before you start! You will need the sqlite3 tool (sudo apt-get install sqlite3).

Two ways to download your pictures from Picasaweb with Linux

There is a nerdy and a simple way. The simple way is to use the google data export ("takeout") pages. You select your photos, create an archive and download it. You may have to upgrade from Picasaweb to Google+ in order for this to work properly.

The nerdy way is via googlecl. Unfortunately this option does not currently work properly due to googlecl still using oauth version 1. But once that's fixed - or if you're still signed into googecl - you can use these two commands:

google picasa list-albums > albums.txt
parallel -a "albums.txt" -j 3 --eta google picasa get "{,}" .

Beware of weird folder names including / or other special symbols. Now you can e.g. move your pictures to your ownCloud server. No picasa needed.

How to change the volume with an active lock screen in android lollipop

This works at least from my Samsung galaxy S4: you press the power button for a few seconds until you see the pop-up to turn off the device, or to go into offline mode. Now you can use the volume buttons to change the ring tone volume.