Linux offers many system monitoring utilities; while some are popular and widely-used, like top, htop, and more, there are others that aren’t as well-known and powerful, although that doesn’t mean they aren’t useful.
Here, in this article, we will discuss one such utility dubbed Saidar which is extremely easy to use and lets you monitor a host of system statistics.
Saidar is a Curses-based tool that comes as part of the libstatgrab library (that provides cross-platform access to statistics about the system on which it’s run) and can be used for viewing several key system statistics including CPU, processes, load, memory, swap, network I/O, disk I/O, and file system information.
In addition to Linux, the libstatgrab library, and hence the tool, is available on several platforms including FreeBSD, NetBSD, OpenBSD, Solaris, DragonFly BSD, HP-UX, and AIX.
Users running a Debian-based distribution like Ubuntu can download and install the utility using the following command:
sudo apt-get install saidar
You can also grab the latest version of the tool by downloading the latest version of the libstatgrab library and building it from scratch.
Here are some examples that explain how the utility can be used.
Note: all examples presented in this article are tested on Ubuntu 14.04.
To view the default output of the command, just run it without any command line option. Here is an example of the output it produced on my system:
As you can see, the tool produced a lot of information in the output which gets updated (or refreshed) in real time after a fixed interval. The first row contains information related to hostname, uptime, and date, while the second and the third rows contain detailed information related to processor and memory, respectively. Towards the end, the output displays information related to disk I/O and network interfaces, as well as the file system.
Change the refresh delay using the -d option
By default, the delay seconds between updates is 3, which means that saidar refreshes its output after every three seconds. However, it also provides a command line option
-d through which you can adjust the delay as per your requirement.
So for example, to set a delay of five seconds, all you have to do is:
saidar -d 5
Enable coloured output using the -c option
For a better view, you can also configure saidar to produce coloured output. This can be done using the
-c command line option. Here is an example:
As you can see in the output, each area has a different colour to distinguish it from the nearby fields. Here are some of the benefits of using the coloured output:
- The load average figures are displayed in bold when they’re notably (greater that 1) different to each other, showing that a change in the load is occurring.
- If CPU usage goes over 60 percent, the command displays it in bold, and at 90 percent the field is displayed using reverse video. The same applies to memory, swap, and disk usage at 75 percent and 90 percent, respectively. Zombie processes are also highlighted.
The Saidar command might not provide advance features like other popular system monitoring tools, but its ability lies in the fact that it displays most of the important system parameters that you’d like to monitor, and gives you a real time view of these statistics. Besides, the utility is also extremely lightweight.
Have you ever used Saidar? How was your experience? Share your thoughts in the comments below.