Thursday Nov 26, 2009

(Can't)Delete files when no space left on disk!!!

It had been a long time since I had used my OpenSolaris. So I wasn't actually aware of the state of the system. I got this nice little icon at the top telling me to update my Operating System. So I just clicked on the link and the update was on its way. It was around 350MB download and I waited patiently for the download to complete. After the download, IPS started to create a new Boot environment and then suddenly it stopped and gave me an error message that there is no free space left in my system. Wow!! Great! Now I have to delete the files and then download again!! x-(

So, I went to my home directory and tried deleting some files. But, Oops!! OpenSolaris came up with this message: "There is not enough memory to delete the files".  I thought that if I reboot my system, things will be back to normal. So I tried rebooting... but gosh!! OpenSoalris refuses to boot!!! Aargh!! what should i do now???? 

I did the most obvious thing... logged into another system and went to the OpenSolaris forum and found the solution! :-)

All I had to do was the following:

1. Log in to maintenance mode (as root).

2. Delete some zfs snapshots.

3. Reboot.

To list all the snapshots, all I had to do was run the following command:

zfs list -t snapshot

To delete the snapshot I had to run the following command:

zfs destroy snapshot_name

Thats it..... :-)

There are 2 things, however, that needs clarification:

1. Why didn't IPS issue a warning when there was very less space in the system?

2. Why was I not able to delete files when the file system is full?

I guess these are bugs that need to be solved. You can follow the bug on bugzilla here:

Tuesday Apr 28, 2009

GUI wizard to configure PPPoE connection for OpenSolaris (Updated)

One of the main criteria for the success of an Operating System is its usability. People generally prefer to go with those OS that provide a user friendly environment. 

The main thing a person wants in the OS is the ability to connect to the internet easily. Now for developers like us, well... we can survive with command line interface and get our work done. But for common man, well... CLI is impossible...

In an effort to make connection to internet using PPPoE easier for OpenSolaris, I have created a GUI Wizard, that lets the user configure his/her connection, connect to the internet as well as disconnect from the internet.

Now the application works great at my place. Just to make sure that it works well on all systems, i would like some of you to try the application and let me know if there is any problem. Any suggestion to improve the wizard would also be really helpful.

Visit : for the GUI executable.

The associated documentation can be found at:

Looking forward to your comments :)

PS: you can mail your comments to nischal(dot)rao(at)sun(dot)com or rao(dot)nischal(at)gmail(dot)com

Tuesday Mar 31, 2009

OpenSolaris Unleashes the power of Intel Nehalem

According to Moore's law, the number of transistors that can be placed inexpensively on an integrated circuit has increased exponentially, doubling approximately every two years. That means that frequent change in the electronics field is inevitable. As and when the hardware capabilities improve, it is important that the software takes advantage of the improved hardware capability. So, is Sun making sure that its software takes advantage of the improved hardware? Yes, it does...

Sun and Intel, as part of a strategic alliance, have been collaborating for over two years to enable the Solaris OS to unleash the power and capabilities of the new Intel Xeon processor 5500 series. As a result, the combination of the Solaris OS and the new Intel Xeon-based systems delivers the highest x64 performance, energy efficiency, and reliability available anywhere. Solaris is "aware" of what the new hardware is able to do and takes very good advantage of it. 

The main area where the OpenSolaris team has been concentrating on is the power management and CPU utilization.

The OpenSolaris team has developed the "PowerTOP" tool, based on Dtrace, which enables the user to observe the power consumption in the system. This is a very important tool mainly because it shows the developers the inefficiencies in the Solaris OS and gives them a chance to improve the OS. Nehalem has a Turbo mode which enables the processor to operate at a very high speed by over-clocking itself. This is ordinarily difficult to observe. But with the help of the PowerTOP it is very easy to observe the system.

Taking advantage of the results of PowerTOP, the OpenSolaris community has started the "Tickless Kernel Architecture" project. Normally even when the OS is idle almost 10% of the time is spent on background processing like clock interrupts which occurs about 100 times a second and most of the time it happens for no reason at all. Its like instead of setting alarm to wake you up at the time you actually want to wake up, you set it to ring every 10 minutes. The goal of the project is to re-implement the service provided by the clock(), so that there is no need for the system to wake up only to find out that there is no work to do. Another area where it is useful is the area of virtualisation where the clocks from different instances of the running operating systems have to be managed.

The other cool thing that i would like to mention here is the "Power Aware dispatcher". Here the dispatcher is working in close coordination with the CPU power management system. The dispatcher communicates with the power management system what resources it is using so that the power management unit can manage the power more efficiently. As a result we have nearly 20% reduction in the idle power consumption. The other important thing is that it is all event driven. There is no polling to wake up. And this leads to an increased performance gain. It is also a "greener" way of using the system.

The next really important feature that has been incorporated is the microcode update and the faster reboot. The microcode update feature lets us to fix bugs in the intel processor without update to the BIOS. It also provides a dynamic update mechanism that lets us apply the changes even when the system is running. So now you don't have to shutdown the system, go to BIOS and do the changes. We also have the fast reboot feature that bypasses the BIOS and as a result we have an increased reboot efficiency.

To improve reliability, the Solaris platform also provides predictive self-healing capabilities for systems based on Intel Nehalem. The Solaris Fault Management Architecture (FMA), which detects and automatically avoids repeated hardware faults in system components, has been extended to utilize status information from Intel Nehalem.

With these features, Sun and Intel have achieved two new world-record benchmarks for Solaris on the Intel Xeon processor 5500 series:
  • Two-tier SAP SD Standard Application Benchmark - This benchmark highlights the optimal performance of SAP ERP software on Intel Xeon-based systems from Sun as well as seamless multilingual support available for SAP ERP applications.
  • Thomson Reuters Market Data System Benchmark - This new benchmark demonstrates that Solaris 10 OS has a very robust implementation of 10Gb Ethernet protocol -- and that deploying traditional RDMS topology over that network infrastructure can result in throughput of up to 850,000 messages per second with end-to-end latency of less than one millisecond.
It gives me great pleasure in informing that Intel has embraced Solaris as "the" enterprise class, mission critical UNIX OS for the Intel Xeon processor-based servers. I believe that this is just the beginning. I am sure the Solaris team and the OpenSolaris community in particular would continue to achieve greater success in future.

Thursday Dec 11, 2008

OpenSolaris2008.11 - The Best Ever

OpenSolaris2008.11 is massive improvement over the OpenSolaris2008.05!! Download the OS today!![Read More]

Sunday Nov 02, 2008


OpenGrok is a fast and usable source code search and cross-reference engine. It enables us to search, cross-reference and navigate the source tree. It is considered the fastest search engine for programs. It can search for full text, definitions, symbols, path and revision history.

OpenGrok is currently an open source project for opensolaris. Various versions of OpenGrok have already been released. A lot of work still goes on to improve the search experience as well as fix certain bugs. For more details on OpenGrok project visit:

[Read More]

Nischal Rao


« June 2016