Troubleshooting

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 much 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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Missing Memory

by on March 13, 2009 · 8 comments

Today, I’ve upgraded total 8 servers from 4GiB to 8GiB to improve performance of system by inserting additional memory modules. We started each server and checked for memory count at console. All severs booted normally after the upgrade and services such as SMTP, NFS, CIFS, HTTP started as expected. Shortly, afterwords I got a call from help desk about pop3 server for slow performance.

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Debian version 5.0 has been released. It is recommended that you upgrade the system to latest version. Upgrading remote Debian server is a piece of cake. In this tutorial, you will learn about upgrading Debian Linux server from Etch to Lenny over ssh session.

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I’m having some weird problem with Firefox 3.0.4 under Ubuntu Linux. My test server runs inside VMWare server version 2.0. It was working fine with my Laptop. But with my desktop it started to dump errors for me. when I try to open the console of a virtual machine I have following error:

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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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I’ve three nameserver load-balanced (LB) in three geo locations. Each LB has a front end public IP address and two backend IP address (one for BIND and another for zone transfer) are assigned to actual bind 9 server running Linux. So when a zone transfer initiates from slave server, all I get errors. A connection cannot be established, it tries again with the servers main ip or LB2 / LB3 ip. This is a problem because my servers are geo located and load balanced. However, there is a small workaround for this problem.

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I’ve already written about Linux process accounting under Linux ( see how to keep a detailed audit trail of what’s being done on your Linux systems). You can easily setup process accounting under FreeBSD. This tutorial expalins how to enable and utilizing FreeBSD process accounting including many other useful options are explained to keep track of system resources used, and their allocation among users.

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