firewalld is the new default firewall for Fedora and RHEL/CentOS. Learning new things can be intimidating at first but after a quick primer I think you’ll find that
firewalld is easier to use for basic firewall setups when compared to
DNF has replaced YUM as the package manager for Fedora 22 onwards and future RHEL/CentOS releases. Luckily, DNF and YUM are very similar, particularly for commonly used commands, but there are some differences. Below are some links I’ve found handy for getting familiar with DNF.
Most Linux distributions do not enable TRIM by default for a variety of reasons. To get the best long-term performance from your SSDs you’ll want to enable it manually. The best way to do this is to occassionally run the
fstrim command on your SSD mount points.
Create a cron script that will run once a day:
sudo touch /etc/cron.daily/fstrim
Add the following to
/etc/cron.daily/fstrim. In this example I have two mount points that I want to TRIM on my SSD, / and /home:
#!/bin/sh LOG=/var/log/fstrim.log echo [ $(date) ] $(fstrim -v / 2>&1) >> $LOG echo [ $(date) ] $(fstrim -v /home 2>&1) >> $LOG
Save the file and then make it executable:
sudo chmod +x /etc/cron.daily/fstrim
It will run once a day and log to /var/log/fstrim.log:
[ Sat Oct 18 08:42:50 MDT 2014 ] /: 42.7 GiB (45856079872 bytes) trimmed [ Sat Oct 18 08:42:51 MDT 2014 ] /home: 101.5 GiB (108950966272 bytes) trimmed
If you’re using LVM or disk encryption the instructions will be different. In that case I recommend you read through the relevant sections in the Arch wiki page for solid state drives:
If your computer is booting with a UEFI BIOS you may notice that changes you make to
/etc/default/grub are not taking effect. This may be because you are generating
grub.cfg in the wrong location.
Make your changes to
/etc/default/grub (kernel options are set on the
GRUB_CMDLINE_LINUX= line). Now regenerate your grub.cfg, both in the standard location:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
And in the location that your UEFI BIOS will actually use:
sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
Alternatively, you can reference your grub config via the symbolic link in
/etc. On UEFI:
sudo grub2-mkconfig -o /etc/grub2-efi.cfg
On non-EFI BIOS:
sudo grub2-mkconfig -o /etc/grub.cfg
I’m running Firefox 32.0.2 on Fedora 21 and I noticed that sites that use Helvetica look very poorly. Here’s a side-by-side comparison of Firefox and Chrome showing the problem:
I found a lot of complaints online regarding this issue, dating back several years, so I doubt this is a recent bug that will be fixed anytime soon. Luckily there’s a simple fix via Firefox’s userContent.css file.
BitTorrent Sync is a powerful cross-platform file sharing application. Think of it as a decentralized version of Dropbox with no charges (it’s free), no limits, and no middle-man.
btsyncctl is a simple bash script I wrote to automate the process of starting, stopping, and checking the status of the BitTorrent Sync application (
btsync) running on a Linux desktop or server.
btsync runs as a non-privileged user and any user with adequate sudo privileges can use
btsyncctl to pass it basic controls like