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Linux Find Out If PCI Hardware Supported or Not In The Current Running Kernel

A typical question from my mailbag:

How do I find out if a given PCI hardware is supported of by the current CentOS / Debian / RHEL / Fedora Linux kernel?

You can easily find out find out if a given piece of PCI hardware such as RAID, network, sound, graphics card is supported or not by the current Linux kernel using the following utilities under any Linux distributions.
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Linux x86_64: Detecting Hardware Errors

The Blue Screen of Death (BSoD) is used by Microsoft Windows, after encountering a critical system error. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem. MCE can detect:

  • Communication error between CPU and motherboard.
  • Memory error - ECC problems.
  • CPU cache errors and so on.

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ss: Display Linux TCP / UDP Network and Socket Information

The ss command is used to show socket statistics. It can display stats for PACKET sockets, TCP sockets, UDP sockets, DCCP sockets, RAW sockets, Unix domain sockets, and more. It allows showing information similar to netstat command. It can display more TCP and state information than other tools. It is a new, incredibly useful and faster (as compare to netstat) tool for tracking TCP connections and sockets. SS can provide information about:

  • All TCP sockets.
  • All UDP sockets.
  • All established ssh / ftp / http / https connections.
  • All local processes connected to X server.
  • Filtering by state (such as connected, synchronized, SYN-RECV, SYN-SENT,TIME-WAIT), addresses and ports.
  • All the tcp sockets in state FIN-WAIT-1 and much more.

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Tips To Protect Linux Servers Physical Console Access

This is an user contributed article.

Linux computer console is a physical device to operate a computer / server. Here are few steps which, if taken, make it more difficult for an attacker to quickly modify a system from its console.
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Linux Convert ext3 to ext4 File system

Some time ago ext4 was released and available for Linux kernel. ext4 provides some additional benefits and perforce over ext3 file system. You can easily convert ext3 to ext4 file system. The next release of Fedora, 11, will default to the ext4 file system unless serious regressions are seen. In this quick tutorial you will learn about converting ext3 to ext4 file system.
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VMWare ESX4 and ESX3.5: SCSI timeout For Linux Guest

Recently, I noticed that the timeout values differ on CentOS v5.x and RHEL Linux 5.x guests on VMWare ESX4 and ESX3.5. I've notices that older ESX 3.5 set a 60 secs timeout and ESX4.x set to 180 secs. Luckly you can fix it easily:
Edit /etc/udev/rules.d/99-vmware-scsi-udev.rules,
# vi /etc/udev/rules.d/99-vmware-scsi-udev.rules
Sample config:

RUN+="/bin/sh -c 'echo 180 >/sys$DEVPATH/device/timeout'"

Find timeout value (180) and change it as per your requirements. Make sure you install the vmware-tools RPM.

Tutorial: OpenOffice.Org Mail Merge


Mail merge is a software function describing the production of multiple documents from a single template form and a structured data source. This helps to create personalized letters and pre-addressed envelopes or mailing labels for mass mailings from a word processing document which contains fixed text, which will be the same in each output document, and variables, which act as placeholders that are replaced by text from the data source. The data source is typically a spreadsheet or a database which has a field or column matching each variable in the template. When the mail merge is run, the word processing system creates an output document for each row in the database, using the fixed text exactly as it appears in the template, but substituting the data variables in the template with the values from the matching columns.

This technique of merging data to create mailshots gave rise to the term mail merge. OpenOffice.Org has a in built software mail merge feature.

If you haven't tried OpenOffice.org's mail merge feature because you find it confusing or difficult to use, you are in luck. Mail Merges in OpenOffice.org and StarOffice provides a detailed description of the mail merge feature from start to finish. Among other things, it shows how you can use the mail merge to create letters, labels, and envelopes.

=> You can download this excellent PDF ebook for your persusal or read the article online - Mail Merge in Openoffice.org: Everything You Need to Know