Bit Note

In my previous post, I provided some information about how to add swap space on Linux.
Recently, I installed an application on my Sun Ultra 10 machine (quite old but still usable) and this application requires a decent amount of memory. To meet this requirement, I only added swap space.

Here's how to add swap on Solaris:
1. Create a swap file. Let's say I need 2GB of swap on a partition that has a lot of available disk space (e.g. /export/home).

# mkfile 2g /export/home/swap_file

2. Add the file to the swap area.

# swap -a /export/home/swap_file

Check the swap space info to verify.

# swap -l
swapfile dev swaplo blocks free
/dev/dsk/c0t0d0s1 136,1 16 4195280 4195280
/export/home/swap_file - 16 4194288 4194288

A lot of IT admins are good at setting up IT infrastructure, fixing hardware and software related issues, securing the network, and other IT stuff. However, writing documentation is the lasting thing most techie persons want to do.
As a result, maintaining these IT assets can be a pain due to poor or lack of documentation.

No one knows where to find the hardware that hosts the company's services, who is the owner of such device, and what softwares are installed on which machine, and whether the softwares are patched or not. To add to this pain, if the IT admin leaves the company, it would require a lot of time for the new hire to get familiarized with the IT infrastructure. This results to loss of productivity, and worse, long downtime in case of service outtage, which costs some money.

Two free open source tools, OCS Inventory NG and GLPI, help IT admins to manage their IT assets. There can be more products that do the same thing, but these two are the best candidate so far as they are free. Combining these two provides a very powerful IT asset management system.

Open Computer and Software Inventory Next Generation (OCS Inventory NG) is a free open source software that enables IT admins to create an inventory of their IT assets and manage them through a web interface. This allows IT admins to know the devices that are connected to their network and which software and hardware component are installed on a computer, and to deploy softwares on their computers.

"GLPI is the Information Resource-Manager with an additional Administration- Interface. You can use it to build up a database with an inventory for your company (computer, software, printers...). It has enhanced functions to make the daily life for the administrators easier, like a job-tracking-system with mail-notification and methods to build a database with basic information about your network-topology." (source http://glpi-project.org )

Preparing the system that hosts OCS and GLPI

I have been checking the traffic statistics of my blog lately using statcounter.com and something caught my attention. Firefox is the on top spot among the browsers used to visit my blog. This is followed by Google Chrome.

My Pinnacle Showcenter 200 has recently stopped working. It turned on using the power button, but it did not respond to the remote control. At first, I though it was remote control's fault, so I decided to change the batteries which did not help.
I was thinking of returning the device to the vendor. But, the warranty has already expired.
After searching Google, I found some information from users which had similar problem. Pinnacle told him that the device was out of warranty and they will repair the device for a fee, and they will gladly help dispose it properly if it cannot be repaired. Another user said that his device was repaired by simply replacing the capacitors.So, I opened the device and found two bulging capacitors on the PSU (power supply unit). Bulging at the top of a capacitor is a sign of failure. 

Caching of DNS queries avoids re-querying of hostname from the DNS server, and therefore improves the performance of the system.
This instruction enables Solaris system to cache DNS query results.

1. Edit the file /etc/nscd.conf and change the following line:

From:

# enable-cache hosts no

To:

enable-cache hosts yes

2. Restart the nscd daemon.

# /etc/init.d/nscd stop

# /etc/init.d/nscd start

I always setup Solaris with minimum packages installed (Core Installation) for security reason, and oftentimes I encounter package dependency problem on a lot of applications I install.
The challenge is, how to know what packages the application requires? This is where the "pkgchk" command comes in handy.
First, you have to check what libraries the binaries of the application requires by using "ldd" command.
e.g.
# ldd file1

This command displays several files that are required by file1.
Next, check which which Solaris package the files belong to by using "pkgchk" command. You need to run this command on a Solaris machine that has all the packages installed (Entire Distribution).

For example, to check which package "truss" file is found:
-----

# pkgchk -l -p /usr/bin/truss

Pathname: /usr/bin/truss

Type: linked file

Source of link: ../../usr/lib/isaexec

Referenced by the following packages:

SUNWtoo

Current status: installed

-----

These commands can be add in a shell script to automate the package dependency check.

A lot of Linux applications are available only as source code. Redhat, SUSE, and other Linux distributions uses RPM package management which makes it easier to distribute and keep track of installed applications through the RPM database.

To create an RPM database, you need to install a Linux package called checkinstall. This is available from the Redhat or SUSE installation CD.
Then, do the following:

1. Unpack the source code of the application.

2. Compile it.

3. After compiling, execute

# checkinstall

That's it. An RPM package is created.