Virtual Machine Manager (virt-manager) doesn’t automatically start your virtual networks. This leads to the following error when starting a vitual machine
Error starting domain: Requested operation is not valid: network 'default' is not active
To solve this error, on Virtual Machine Manger go to Edit->Connection Details->Virtual Networks, select the required network (‘default’ in our case) and press the Start Network button (has a play-button icon). You can avoid having to go through this process by ticking the Autostart checkbox, which will make the network start automatically at boot.
Google Photos imposes a 100 megapixel limit on uploaded photos. This may sound like a lot, as even the very high-end Sony Alpha a7R III has “only” 48MP sensor, but in reality when you shoot panoramas and stitch them yourself, you can quickly get there, and hit the 100MP limit. When you try to upload your huge panorama to Google Photos, you will get a
A photo or video was skipped
To solve it, you need to resize your image and make it smaller. This can be done automatically using ImageMagick’s convert:
$ convert -resize "100000000@>" panorama-in.jpg panorama-out.jpg
This will resize the
panorama-in.jpg to at most 100MB, and save it as
> makes sure we will only down-size larger photos.
By default under Debian, ImageMagick comes with a very strict `policy.xml` controling the resources it can use. Practically, it means that unless you change those limits, you’ll encounter resource limit errors such as:
convert-im6.q16: width or height exceeds limit `panorama-in.jpg' @ error/cache.c/OpenPixelCache/3802.
To solve it you will need to edit
/etc/ImageMagick-6/policy.xml and increase the limit for memory, width, height and area. For example:
<policy domain="resource" name="memory" value="8GiB"/>
<policy domain="resource" name="width" value="128KB"/>
<policy domain="resource" name="height" value="128KB"/>
<policy domain="resource" name="area" value="8GB"/>
I’ve made available in my personal repository
amd64 builds of Hugin 2018.0.0 for Debian Stretch.
After a recent upgrade to Debian Stretch, my OpenVPN server stopped working. Checking the relevant log file,
/var/log/openvpn.log, I found the following not very helpful error message.
Fri Nov 23 16:46:37 2018 OpenVPN 2.4.0 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on Jul 18 2017
Fri Nov 23 16:46:37 2018 library versions: OpenSSL 1.0.2l 25 May 2017, LZO 2.08
Fri Nov 23 16:46:37 2018 daemon() failed or unsupported: Resource temporarily unavailable (errno=11)
Fri Nov 23 16:46:37 2018 Exiting due to fatal error
Fortunately, someone already reported this error to debian and found out that the error is caused by the
LimintNPROC directive in systemd is used to limit the number of forks a service is allowed to make. Removing this limit, might not be the best idea. So, I would suggest that instead of commenting it out, to find out the minimal value that allows OpenVPN to start and work. After some testing, I found that the minimal value that worked for me is
After editing the
/lib/systemd/system/openvpn@.service, you need to reload the systemd service files and restart the OpenVPN server process.
$ sudo systemctl daemon-reload
$ sudo systemctl restart openvpn@server