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Technology is the term we use for things that don't quite work yet.

iptraf
So I’m a pretty technical gal and sometimes I know what I want to do, but I have no idea how to do it with the latest version of whatever operating system I’m using. Typically these days thats usually a Linux flavor of some sort. I use it for my web-server, my file server and a few other things, but typically I set it up leave it and don’t touch it for a year or so. So instead of having to troll through man pages every time I want to do something, I started to keep a list of not-frequently used commands that I always seem to forget. So this is sort of an anti-FAQ for Linux. I mean if they were frequent, i wouldn’t forget!

Scan for viruses manually with clamscan – Most of this is excluding the test directories and system devices.

clamscan -ir –exclude=/sys/ –exclude=/usr/share/doc/clamav-0.95.1/test/ /

Firewall aka. IPTables
Block IP address – * for a range

iptables -I INPUT -s 192.168.0.* -j DROP

List IP’s instead of RDNS

iptables –list -n

Delete the 3rd rule

iptables -D INPUT 3

Remove file with crazy name – Ever mange to munge a filename so bad rm won’t remove it?

ls -il
find . -inum 124043383 -exec rm -i {} \;

Hard disk tweaking – not sure how much this helps but it helped me.

cd /sys/block/sda/queue/iosched/
echo 1000 > write_expire
echo 0 > slice_idle
hdparm -Tt /dev/sda

SMART Hard Disk Check– run smart report if you have a Highpoint controller that supports it. Remember to run a periodic short/long test. I’ve found the basic report is often inadequate.

smartctl -a -d hpt,1/1 /dev/sda

Yum locate dependency- some package failing because it needs some dependency? This was a real lifesaver.

yum whatprovides yourlibraryhere

Did something before but forgot? grep the .bash_history file, it seems to keep everything from the beginning of time.

iptraf traffic statistics– need to know traffic flow on your machine right now? Yeah you could do some sort of netstat command but I can never figure it out on the local platform (its “netstat -I en0 -w 1” on OS X).
This app will give you all sorts of useful live statstics on your ethernet connections.

Next time – SELinux – all you need to know to setup your apache/php/centos webserver.

P.S. Any useful commands you use that you think might be helpful? Leave a comment :)

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