e-ignite: Tech

There have been many times I’ve sat at my computer wondering how to do such-and-such on Fedora Linux and haven’t been able to find a straight answer through all of my efforts on Google. I recently came across the Fedora Guide which has an excellent page of “how to” questions and answers. The Fedora Guide keeps it simple – for example, “How To Install Google Desktop” simply shows you the command you need to enter in Terminal (for Google Desktop, all you need to do is enter su -c ‘yum –enablerepo=google install google-desktop-linux’)

I found a number of entries I found useful, and even managed to enable several things I didn’t realise I missed from Windows, such as backspace to go “back” in Firefox. A few of my favourite tweaks are listed below:

Setting the backspace button to go to a previous page
Open Firefox and enter about:config into the address bar
In the Filter field, enter browser.backspace_action and change the value to 0 (the number zero)

Improving your bandwidth
Open Terminal and enter the following commands:
su -c ‘cp /etc/sysctl.conf /etc/sysctl.conf.backup’
su -c ‘gedit /etc/sysctl.conf’

Add the following lines to sysctl.conf:
## increase TCP max buffer size setable using setsockopt()
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
## increase Linux autotuning TCP buffer limits
## min, default, and max number of bytes to use
## set max to at least 4MB, or higher if you use very high BDP paths
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
## don’t cache ssthresh from previous connection
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
## recommended to increase this for 1000 BT or higher
net.core.netdev_max_backlog = 2500
## for 10 GigE, use this, uncomment below
## net.core.netdev_max_backlog = 30000
## Turn off timestamps if you’re on a gigabit or very busy network
## Having it off is one less thing the IP stack needs to work on
## net.ipv4.tcp_timestamps = 0
## disable tcp selective acknowledgements.
net.ipv4.tcp_sack = 0
##enable window scaling
net.ipv4.tcp_window_scaling = 1

Save and close the file, then run the following command in Terminal:
su -c ‘/sbin/sysctl -p’

Deleting files securely
To “shred” a file (overwrite it several times to prevent it being recovered), open Terminal and brose to the folder that contains the file you want to shred (for example, if it is on the Desktop enter cd /home/<user>/Desktop) and then enter the following command:
shred -z -u yourfile (where “yourfile” is the file you want to destroy, for example “secret.doc”)

These are just a few of the commands that I found useful, but why not head over to the Fedora Guide and see what other tips and tricks you can find.