Allow WiFi to start before you log in [Archive] DizzyTech July 16th, 2009, 08:05 PM I often find myself, despite having a lightning-fast boot with Ubuntu, waiting at my desktop for something to start. I started looking at what I do with my computer, investigating my bottlenecks. One of them was my wireless network. Even though I have a perfectly functional wireless card and I work within mere feet of my router, I often find myself waiting for the wireless to start before opening my web browser. Background: I recently had a brief stint with Arch Linux due to, well, curiosity. Most modern Linux distributions include NetworkManager, a very powerful network management daemon. NetworkManager can support automatically unlocking itself and signing in to networks immediately upon the daemon starting. Steps: Still with me? Make sure you are logged in to the account on your Ubuntu computer that manages wireless networks.
Gksudo gedit /etc/pam.d/passwd A text editor window should open. Password optional pam_gnome_keyring.so Hit Alt+F2. Undo! Top, ps, sar which gives accurate data for CPU utilization. Linux - Understanding the counters in /proc/[pid]/io. C - Calculating CPU usage of a process in Linux. Procstat - displays linux proc stat (/proc/pid/stat) in human-readable format. Small tool to translate cryptic info from /proc/*/stat into understandable form. Actually, ps shows most of things needed.
But this will show you everything at once in mostly raw format. Read man 5 proc about meaning of fields. Or just ask me here. Note, on the man page field names has underscore removed. In kernel source it is on its place. Without arguments procstat reads stat info from stdin. Download: procstat.c (4k) Build: gcc -o procstat procstat.c kef@flash:~$ . How to Use the /proc Filesystem to Examine Your Linux Inner Working. Quick – answer me this: How much swap space is in use on your system right now?
How big is the cache on your CPU? What kernel modules are currently loaded? How many total drives and partitions are you running? If you’re running Linux, all these questions (and a whole lot more) can be answered one easy way: take a look in /proc. It’s a goldmine of system information, just waiting to be retrieved by users, administrators, and scripts. In this guide we’ll take a trip through /proc to see just what valuable system information you’ve been missing out on. About /proc Probably the most important thing to understand about /proc is that it’s not a normal directory with normal files.
By putting this kind of system information into a virtual filesystem like proc, the developers adhere to the UNIX philosophy “everything is a file”. Note: The files mentioned here should all open cleanly in any text editor of your choice. /proc/cpuinfo /proc/meminfo /proc/cmdline /proc/filesystems /proc/PID /proc/modules. How to kill a TCP connection using netstat. Linux: How to kill a TCP connection using netstat? You cannot kill a TCP connection using netstat utility. netstat is use for Display network connectionsRouting tablesInterface statisticsMasquerade connectionsMulticast memberships And much more However Linux support two other commands or utility that can be used to kill a TCP connection. tcpkill command Use tcpkill command to kill specified in-progress TCP connections.
It is useful for libnids-based applications which require a full TCP 3-whs for TCB creation. Syntax: tcpkill -i eth0 { expression } Examples: (a) Kill all outgoing ftp (port 21) connection: tcpkill -i eth0 port 21 (b) Kill all all packets arriving at or departing from host 192.168.1.2 (host12.nixcraft.com) tcpkill host 192.168.1.2 tcpkill host host12.nixcraft.com (c) To kill all IP packets between 192.168.1.2 and any host except 192.168.1.111, type the following: tcpkill ip host 192.168.1.2 and not 192.168.1.111 cutter command Related articles. 20 Linux System Monitoring Tools Every SysAdmin Should Know.
Need to monitor Linux server performance? Try these built-in commands and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as: Finding out bottlenecks.Disk (storage) bottlenecks.CPU and memory bottlenecks.Network bottlenecks. #1: top - Process Activity Command The top program provides a dynamic real-time view of a running system i.e. actual process activity.
Fig.01: Linux top command Commonly Used Hot Keys The top command provides several useful hot keys: => Related: How do I Find Out Linux CPU Utilization? #2: vmstat - System Activity, Hardware and System Information Display Memory Utilization Slabinfo # vmstat -m Get Information About Active / Inactive Memory Pages.