IT News & Technology update

Tuning the Linux kernel for more aggressive network throughput

Written by IT News on 5:40 PM

The Linux kernel and the distributions that package it typically provide very conservative defaults to certain network settings that affect networking parameters. These settings can be tuned via the /proc filesystem or using the sysctl program. The latter is often better, as it reads the contents of /etc/sysctl.conf, which allows you to keep settings across reboots.

The following is a snippet from /etc/sysctl.conf that may improve network performance:

net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_syncookies = 1
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216

The above isn’t to replace what may already exist in /etc/sysctl.conf, but rather to supplement it. The first command enables TCP window scaling, which allows clients to download data at a higher rate by enabling extra bits in TCP packets that are used to increase the window size.

The second command enables TCP SYN cookies, which is often enabled by default and is extremely effective in preventing conditions such as SYN floods that can drain the server of resources used to process incoming connections.

The last four options increase the TCP send and receive buffers, which allow an application to move its data out faster so as to serve other requests. This also improves the client’s ability to send data to the server when it gets busy.

By adding these commands to the /etc/sysctl.conf file, you ensure they take effect on every reboot. To enable them immediately without a reboot, use:

# sysctl -p /etc/sysctl.conf

To see all of the currently configured sysctl options, use:

# sysctl -a

This will list all of the configuration keys and their current values. The sysctl.conf file allows you to configure and save new defaults; what you see from this output are the defaults defined in the kernel that are currently effective. To see the value of one particular item, use:

# sysctl -q net.ipv4.tcp_window_scaling

Likewise, to set the value of one item without configuring it in sysctl.conf — and understanding that it won’t be retained across reboots, use:

# sysctl -w net.ipv4.tcp_window_scaling=1

This can be useful for testing the effectiveness of certain settings without committing them to being defaults.

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| Posted in » kernel, Linux, Network

ASUS and Intel slaughters OLPC with Eee-ase

Written by IT News on 7:09 PM

ASUS and Intel have actually created an alternative for Nicholas Negroponte’s OLPC (One Laptop Per Child) called the “Eee PC”. The difference here is that the ASUS Eee PC is actually something that looks usable and perhaps even desirable for everyday use as a super cheap UMPC (Ultra Mobile PC).

The ASUS Eee computer will cost a mere $199 for the 7″ LCD model whereas the so-called $100 OLPC costs $175. Given the fact that Eee can run Linux or Windows XP and it can boot off NAND flash memory in a mere 15 seconds, the Eee slaughters the OLPC with ease.

The OLPC was originally slated to be the $100 PC but the actual production cost is somewhere around $175. I had a chance to get a test drive of the OLPC at the CTIA wireless conference and it was probably the worst computing experience I’ve had in a long time. The rubberized keyboard was virtually stuck to the surface with almost zero tactile feedback and the Operating System of the OLPC spends a painful 2-3 minutes to boot. Even launching a new application seems to take an eternity.

The user interface of the OLPC doesn’t even feel worth of a cheap fisher price toy. If I were to rank it, it would be somewhere above DOS and far below Apple’s Lisa (predecessor to the Mac Operating System). I can’t wait to test drive the Eee PC.

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| Posted in » Asus, Hardware server, Intel, Technology

Turn off drawing canvas in Office 2003

Written by IT News on 6:30 PM

When you create any drawing object in Office 2003, by default it will create a new drawing canvas, many users hate this featur and ask me how to disable it?

Follow this step to disable the drawing canvas in Office 2003 (word, excel, power point)

Open Microsoft Word, from the Tools menu click Option;
Choose general tab;
Clear or uncheck Automatically create drawing canvas when inserting Autoshapes

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| Posted in » drawing canvas, office 2003, Tips, word

Turn off gridlines in your Excel applications

Written by IT News on 6:29 PM

Your users may find it easier to work with your worksheet applications if they can't see the gridlines. For example, let's say you developed a worksheet that displays a new chart that compares monthly sales figures for the department each time a salesperson enters his/her monthly sales figures. Your worksheet includes instructions for using the spreadsheet, a bordered cell where they are to enter their data, and the changing chart.

To prevent the salespeople from working with the other cells in the worksheet, you can turn off the gridlines in Excel 2003 or Excel 2002, by following these steps:

Go to Tools | Options.
On the View tab in the Windows section, clear the Gridlines check box.
Click OK.

To turn off the gridlines in Excel 2007, follow these steps:

Click the View tab.
Clear the Gridlines check box in the Show/Hide section of the ribbon.

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| Posted in » Computer, Excel, Excel tips, Microsoft

50 essential Excel tips

Written by IT News on 11:22 PM

his message is loaded with valuable information that can save you time and effort. Below, you’ll find a sample of what the Excel TechMail has to offer. Get valuable tips on macros, formulas, formatting workbooks, links to Excel resources, and much more, all delivered straight to your inbox every weekday.

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| Posted in » Computer, Excel tips

Google acquires FeedBurner

Written by IT News on 10:18 PM

Just in case you missed it, the latest Google acquisition news is in: Google has acquired FeedBurner.

FeedBurner is a company that distributes syndicated content for blogs and other media Web sites. It is best known by how it simplified the process by which users create drop-down boxes in browser windows to receive continuous updates from preferred publishers of news, blogs or other web content.

If you are a serious blogger, you will probably already have an account with FeedBurner.

Buying FeedBurner makes sense in that it allows Google to expand its online advertising empire deep into the fast-growing world of direct feeds.

According to Dick Costolo, co-founder and new Google executive: More than 763,000 ‘live feeds’ run through FeedBurner daily delivering content from approximately 430,000 publishers including major news organisations.

To read more: