Posts Tagged programs

Tracking down io problems on your Linux box

Posted by on Tuesday, 16 June, 2009

I’m sure everyone has had problem at one time or another trying to figure out why your machine is going so slow, but nothing appears to be using the RAM or CPU at all.

The first option is to top ‘top’  and look for the line which has the ‘wa’

Cpu(s):  0.0%us,  0.0%sy,  0.0%ni, 96.7%id,  3.3%wa,  0.0%hi,  0.0%si,  0.0%st

mine says 3.3%wa – this is the wait time trying to write to disk. Now from there you can install the package (under most distros) called ‘sysstat’

sysstat – sar, iostat and mpstat – system performance tools for Linux

This contains several tools for trying to track down whats using the disk to write lots.

iotop – simple top-like I/O monitor. This is installed and can show you realtime whats writing to disk at any time and using what load
iostat  –  Report  Central  Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS).
sar – Collect, report, or save system activity information.

If there’s plenty of cache/buffers, and sar -W 1 0 shows lots of zeroes (and possibly the occasional blip) then the disk is getting thrashed, but it’s not swap.

Running iostat -dx 1 will show you all the partitions and how hard they’re working (look at %util). If %util is consistently at or around 100 for any partition of disk, you can definitively say that the disks are getting thrashed.

If the disk has high %util, but the actual throughput (rsec/s and wsec/s) is pretty low, then it’s possible you’ve got a hardware fault or RAID rebuild going on. A hardware error might show up on a smartctl run (smartctl -a /dev/sda or whatever), looking at things like the reallocated sector count, but SMART isn’t real, well, smart, so don’t trust it too much. A RAID rebuild should show up in your RAID management (you are monitoring your hardware RAID setup, aren’t you?). A software RAID rebuild will be shown in /proc/mdstat. (cat /proc/mdstat )


Applications for new users.

Posted by on Tuesday, 7 April, 2009

Often a lot of new users have used windows for several years before switching to linux and half the problem is that they have no idea what the equivalent program is to run. This document is a small idea just to get you started.

Media

I have done this one first because often the first thing i do when installing is want to play either a movie or mp3s.

Video

xine is good for divx vcd dvd and a few others I find , its to be great for most every day movies. Though it isnt that great for things like playlists. Best of all it has a nice gui to work with, and has similar keybindings to windows so doesnt confuse you as much.

Mplayer is a great player and plays even more formats than xine, however its gui isnt that great and its dependant on installing win32 codecs (which isnt that great a hassle). If in doubt i find it plays a lot of streaming formats that xine just doesnt handle. And at a pinch you can use its aalib plugin and play your movies in ascii in console!.

VLC is a less used and yet still good media player. I havnt used it as much but it appears to be quiet handy.

DVD

Ogle is pretty much the only DVD player that supports menus, and although other players play dvds I still prefer ogle for the job. Great gui, nice easy design and use.

MP3s

XMMS is Winamp basicly, Takes most of the themes (well at least the older ones anyway) and even used to be written by the same people (previously known as Linamp). Supports playlists, loading directories and most other usual things from an mp3 player. Great plugins and other options.

MPG123 Is a great console mp3 player, there are a fair few of them so I will limit myself to this one for now. You can use mp3blaster or cplay for playlist abilities in console.

WEB

Email

Evolution Is a great mail client, it looks and feels a lot like Outlook. Its got all the functionality of most decent email clients and looks great.

Kmail Is another great mail client. Good if you are using KDE. Has support for pretty much everything much like Evolution.

Mutt Is a console email program, supports threading and is apparently quiet good to use. I have personally never really used it, but it comes well recommended by many.

WWW

Firefox Is the web developers web browser of choice, its multi platform and works brilliantly. Its quick, and configureable.

Mozilla is a little more bulky and slower than firefox however it contains a great email client, web page composer and other great features. Its also multi platform.

Konqueror Is a lightweight browser and file manager that comes with KDE. Its great for quick opening and a lot of sites are easily viewd under it. It has its drawbacks when it comes to complex javascript or css based sites however.

Files

File Management

Konqueror Is a great file manager that comes with KDE. It can open ftp:// or files over ssh using fish:/ amoung tons of other helpful plugins (CVS via cervisia is also handy). Thumbnail displays and file previews are great.

Nautilus is a File manager that works better with Gnome. It Does pretty much everything Konqueror can do only it works better with gnome.

Chat

IMs

Kopete is a great IM manager, it does MSN, AIM, ICQ, Jabber, IRC, SMS, Yahoo, and Gadu Gadu (whatever that is). It has a nice look to it and it docks in KDE awesomely.

Gaim is the Gnome equivalent to Kopete, looks great and is easy to use for multiple networks.

AMSN is a great stand alone MSN client, very much like the windows one.

LICQ is a good stand alone ICQ client, very much like the windows one, with themes etc.

IRC

Xchat is a great gui IRC client, takes scripts of all sorts and very configureable. A popular choice for a lot of Linux users. Looks similar to mIRC.

Irssi is a popular choice for console based IRC. Though it does have a gui, its text version is by far better to use. Supports windows, themes, colours, etc and all the usual things.

WEB
Graphics

GIMP is pretty much the ONLY decent graphics program for editing and manipulations, Though it is very different to anything in windows in some respects. Its great to use once you are used to it.

Since this is more of an overview I have left a lot of applications out that are also very good. This is enough to get you started with the more commonly used software. Take the time to look at other applications and choose whichever suits you best. Everyone has different needs and requirements and there is plenty of software to go around and play with.

Liz Last-Modified: 2007-03-07 19:38:50