Linux rename network interface using udev rules
Sometimes it is convenient to have user assigned names to network interfaces – particularly when the MAC address of the interface remains constant but the bus on which it is attached may change because it’s a virtual machine.
All that is required to be done is create a file /etc/udev/rules.d/persistent-net.rules : This file used to exist earlier but has been phased out by most mainstream Linux distributions in favor of the consistent naming scheme or other methods like systemd-networkd.
The udev rules required in that file:
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SUBSYSTEM=="net", ACTION=="add", ATTR{address}=="aa:bb:cc:dd:ee:ff", NAME="wan" SUBSYSTEM=="net", ACTION=="add", ATTR{address}=="bb:cc:dd:ee:ff:aa", NAME="lan" SUBSYSTEM=="net", ACTION=="add", ATTR{address}=="cc:dd:ee:ff:aa:bb", NAME="lan2" |
Hibernate support on Ubuntu 20.04 with encrypted swap and encrypted root filesystem
So I installed Ubuntu 20.04 on my laptop with encrypted root filesystem with bcache support since I have a NVME SSD along with the usual hard disk in it. While setting up encrypted root filesystem the installer will not allow you to have unencrypted swap – and the default encrypted swap setup is to use a random encryption key that is […]
Cloning a UEFI/GPT Windows 10 installation from HDD to SSD using SystemRescueCD
So, I had an interesting problem at hand – to transfer a completely working Windows 10 installation from a 1 TB HDD to a 1 TB NVME SSD (Samsung 970 EVO Plus). As someone who has done something of that sort many times, but with Linux based OSes my first thought was if I could do some sort of stuff with a SystemRescueCD running from a USB pen drive – as I wasn’t willing to use any Windows based backup solution since I had no idea how they work, or whether they work at all. To […]
Speeding up PHP CLI applications using OpCache
I run a few PHP based applications which require background jobs, and I use the usual crond via crontab to run the jobs. PHP has an excellent feature – OpCache which can cache the compiled code in memory to speed up the web applications, where typically the PHP-FPM process is a long running process so the compiled code can be fetched on next request. But with CLI applications there is no shared state or memory to store the compiled code.
Golang on OpenWRT MIPS
I have been tracking Golang for quite a while since I came to know about it I guess about 3 years ago primarily because it is very easy to use and build static binaries that just work about anywhere. And no dealing with memory allocation stuff which often lead to frustrations and segmentation fault bugs soaking up hours of your time to solve those.
As a OpenWRT user running a Go program on OpenWRT had been one of my most desired things. So here it is, finally, a hello world program running my TP Link […]
Change username and hostname for Ubuntu instances on AWS
If you have used Ubuntu images on AWS, you might have noticed that the default username of the user on the instance is ‘ubuntu’. And the hostname is dynamically generated according to the public IP. Both of these can be changed using cloud-config supported on Ubuntu images – the config has to be provided in the User Data section in Advanced on the Configure Instance tab.
YAML configuration to change the parameters:
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#cloud-config fqdn: myhostname system_info: default_user: name: myusername |
A lot more things are possible using the cloud-config method and it is supported on other operating […]