Tag: UNIX

Linux is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive UNIX systems. Linux has a reputation as a very efficient and fast-performing system. Linux (often pronounced LIH-nuhks with a short “i”) is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive UNIX systems. Linux has a reputation as a very efficient and fast-performing system. Linux’s kernel (the central part of the operating system) was developed by Linus Torvalds at the University of Helsinki in Finland. To complete the operating system, Torvalds and other team members made use of system components developed by members of the Free Software Foundation for the GNU Project.
Linux is a remarkably complete operating system, including a graphical user interface, an X Window System, TCP/IP, the Emacs editor, and other components usually found in a comprehensive UNIX system. Linux is distributed using the Free Software Foundation’s copy left stipulations that mean any modified version that is redistributed must in turn be freely available. The below mentioned features gives Linux a winning edge once compared to most Operating Systems.
Linux is reliable
Linux runs on your existing machines
Linux is free and requires no costly add-ons
Free Support for lifetime
Linux has no Registry
You don’t need to restart Linux
Linux has no SIDs
Linux has no licensing mechanism
The GUI is optional
Extremely low space required for operations
Linux is multi-platform
Linux uses open protocols
Linux integrates with NetWare
Linux integrates with Windows networks
Linux integrates with Macintosh networks
Linux is a good career move

The head office of Rooman Technology for Linux training is in Bangalore, the highly efficient institute for fulfilling requirements of IT industries, for those who are seeking to get a bright future in computer and IT professionals. It has been considered as the No.1 training company and its Regional branch is in Delhi which provides the same efficiency as the Head office. It has been said that Rooman Technology will open about 100 branches very shortly.
It provides both the full time and part time courses for the candidates. Full time courses are of 10 months and the part time courses are of 5 months. Anyone who seeks to get better knowledge in any source of networking can go for these courses as the rate of fees are quite reasonable and even gives assurance for required placements.

Linux is a clan of operating systems similar to UNIX, based and is fast emerging as an embedded platform for many netbooks and smartphones. The use and development of Linux is at a demanding rate and this comes with an added demand for professionals who are adept at Linux. A Linux certification is always a bonus in such a scenario to display one’s aptitude in the Linux operating system. Linux training is always helpful for future job prospects and is an added feature in one’s resume. Many companies and franchises provide Linux certification courses to help one harness his/her Linux skills.

Many companies provide certification programs in Linux throughout the country. Rates and duration may depend from franchise to franchise and also upon location and the level of additional experience provided. Almost all course providers have an assessment oriented curriculum wherein the candidate is tested with regular or a final exam to display his/ her competence at the Linux language and showcase his skills. Many companies also offer certain experience to their applicants, as a part of their Linux certification courses, by engaging them some or the other practical work.

A beforehand practise or working experience is always a tag to carry around in case one is interested in Linux administration; it is bound to increase further job prospects. Companies may provide a complete training course or domain specific training in Linux. Course content may vary but mostly consists of in depth knowledge of Linux installation and process, network and group management etc. All courses are professionally formulated keeping in with the latest trends and technology.

A Linux Certification has undoubtedly many advantages to professionals and amateurs alike. Linux Training always increases your value and status as a Linux administrator and as a programmer. It gives one a chance to display his/ her expertise at this fast developing operating system. A certification course in Linux is an ideal place to start learning Linux at a deep knowledge level and it also provides one with the right platform to fast pace or jump start one’s career in Linux administration. A lot of companies and enterprises employ professionals practised at Linux and project them as a selling tool for better market acquisition. A certification in Linux morally boosts the morale of IT personnel who have to make extensive use of the related technology.

Internet is booming from the very day it came into being. One of the advantages of internet in the business field is web hosting. Internet has made the world a global village. There are no boundaries. Once you have a website for your business you can expand your business horizon according to your imagination. Big organizations are going for managed web hosting. Linux server has become very popular among big organizations. Linux Hosting India provides top class service in this open source variation of UNIX operating System.

Linux Hosting

Linux is a leading server operating system. In simple words it can be defined as an open source system based on the model of UNIX operating system. Linux Hosting India is a pioneer in this field. Its strong knowledge in web hosting and dedicated server technologies, coupled with vast experience and round the clock customer support is its strength. Linux can be installed in a wide range of computer hardwares, mobile phones, video game consoles to mainframe and super computers.

Linux vs. Windows

Even though windows have reined the operating system and web hosting field for long, big organizations are now switching to Linux. The most prevalent advantage of Linux over windows is its cost effectiveness. Linux is almost free to obtain, while windows product can be owned only after paying a hefty price. Moreover Microsoft licenses are allowed only for one computer, whereas Linux distribution can be installed on any number of computers.

Linux server can be easily converted into windows. Thus conversion to another server is hassle free. But with windows it is very complicated and time consuming. If your website is using languages like PHP, MySQL and Pearl, you must go for Linux server hosting. Linux is basically an open source software product and thus is not bound by any license fees. With Linux hosting India customization can be done in real time.

Linux is an operating system which is very adaptive and flexible when compared to windows. Linux offers several user interfaces to use from when compared to windows. Linux is more secured and reliable when compared to windows. With India Linux Hosting you get cheaper hosting fees, more reliable server with Linux, readily available free program with Linux, greater access and control of files and permissions. Linux provides ever evolving control panel for administrative utilities.

Linux based web hosting scales extremely well, so as your website grows and traffic towards your website increases, it remains easy to manage. Linux Hosting India hosting fulfills ones requirement for good web server and web serving, file serving, mailing and streaming. It is very much cost effective, reliable and secure. Linux Web hosting is deemed to be the most prominent form of web hosting on the internet.

Every UNIX based system like Linux has a certain set of limitations on the kind of feature sets and resources that can be used by a program or user. This can range from simplistic models like the complete length of file’s path, to the kind of arguments and calls that a program can have.

Since these limits effectively reduce the scope and abilities of a program, an application trying to be portable across different UNIX implementations needs to account for varying limit standards. The Single UNIX Specification’s third version (SuSv3, in short) defined three discrete functions that an application could call to determine the limits of the system it was working on – fpathconf(), pathconf() andsysconf(). It also defined a limit range that a UNIX implementation could enforce. The most crucial part of this set range was a minimum limit. This particular limit would be set as a constant in the limits header file, with a name that begun with the _posix_ string. If an application could stick to the specified minimum limits, it would manage to be portable across most implementations in all likelihood. However, that would result in a loss of functionality that higher limit values would bring in. This made determining the limits of a system using sysconf() etc. particularly invariable. This function was also a great tool to determine runtime invariant and increasable values.

A function like pathconf(), on the other hand, deals with the name of file paths. Limits on these pathnames could be determined using functions like fpathconf() and pathconf(). Limits can also be ascertained through shell commands. The getconfcommand can help you determine the limits in the UNIX implementation you are currently working on.

During runtime, sysconf() can tell you the limits you need when you specify the name of the limit in the function’s argument. If the limit cannot be determined, or there is an error of any sort, the function will return a value of –1′. SuSv3 dictates that the value returned by the function has to be constant all through the calling.

The difference between pathconf() and fpathconf() is the method of specifying the file/directory. In the case of the former, the pathname needs to be specified, while for the latter, a previously opened file descriptor is required. SuSv3 does not require these functions to return values than remain constant all through an entire process runtime. This lets a file system to be mounted and dismounted multiple times, all while the process is running.

Indeterminate limits are ones that are not defined by an implementation limit constant. The functions stated above would end up returning –1′ to indicate the indeterminacy of the limits required. These hindrances can be handled in a number of ways – the most practical of them being to avoid the checking of limits, and instead perform the corresponding library function calls. If those calls fail too, the errnomust be checked to judge whether some other system limit was violated, so that you can modify the program behavior accordingly.

You should avoid hardcoding system limit assumptions into your programs, as it may not be valid across every file system or UNIX implementation. Using the necessary functions, SuSv3 can guide you to make your program adapt even in real-time.

With the growing popularity of Linux server solutions, many clients often ask me, “What is the best MTA for my Linux server?”. A Mail Transfer Agent, or MTA, is a software package that allows your Linux server to send and receive mail. There are many different MTAs out there, and each MTA has it’s own specific strengths and weaknesses. This article will cover the more popular MTAs- Exim, Postfix, Sendmail, Qmail, and Zimbra. Although Zimbra is more of a productivity suite than a MTA, it is worth mentioning due to it’s extensive features.

Exim

Exim has been out since 1995, and growing in popularity ever since. The biggest strength of Exim is it’s almost infinite level of customization. Exim supports the ability for a server administrator to create a custom ruleset that handles incoming and outgoing emails in any particular manner. For instance, it is easier with Exim to create a custom rule that routes incoming mail from a particular domain past anti-virus and anti-spam filters. One disadvantage is that Exim has had a less than stellar history with security. Exim3 was vulnerable to numerous security vulnerabilities, but it appears so far that Exim4 is more secure. Although Exim was not designed for performance, Exim can be configured to run as a high performance mail server. Exim is an excellent MTA if you need to create a complex or custom mail configuration. Exim is the default MTA on Debian Linux.

Postfix

Postfix is possibly the fastest growing MTA on the market today. Postfix is extremely popular because of it’s performance, and it’s past security history. It is far harder (or almost impossible) to compromise the root user on a server that runs Postfix, than for instance Sendmail or Exim. Postfix also supports the use of milters, which allow you to use external software solutions to pass mail from Postfix to anti-virus and anti-spam filters. Postfix also runs faster with less system resources than most other MTAs (or at least, with standard configurations). Standard configurations are easy to create, but if you need a unique setup, it can be a pain with Postfix. These strengths leave little mystery as to the sudden growth of Postfix as a Linux mail server software solution. Postfix is the default MTA on Ubuntu Linux.

Sendmail

Sendmail is the most popular MTA. Written in 1982, Sendmail is literally the standard by which all other MTAs are compared. Sendmail has lost most of it’s popularity in recent years though, due to security issues, and a difficult configuration. Sendmail is the most difficult MTA to configure, and has had more than it’s fair share of security vulnerabilities and compromises. The few administrators that run Sendmail either do so for compatibility reasons (it was, after all, the classic UNIX mail server), or for comfortability (UNIX admins will sometimes cling to Sendmail, because they are used to it’s over complicated configuration). Red Hat Enterprise Linux uses Sendmail by default.

Qmail

Qmail is the one of the most secure MTAs on the market today. Although unsupported, and not currently in development (Qmail hasn’t been updated since 1997), Qmail has a large fan base. Qmail is also faster, and scales better with higher mail loads than Sendmail. However, Qmail is not easy to configure, or easy to extend. Qmail does not support Sendmail milters, so any additional filters have to be specifically written for Qmail. Qmail is the default MTA in the popular Plesk control panel software.

Zimbra

Zimbra is the least popular of all the MTAs mentioned. Zimbra is not designed for security, speed, or infinite customization- it is designed for group collaboration. Zimbra is extremely easy to install and configure, but should not be used as a high performance MTA. Zimbra instead excels if you want to have a way to share calendars, files, and contacts with other users on the Zimbra mail server. A web-based control panel allows an easy way to add or remove users from the mail server, and most configuration is just as easy. Zimbra offers a commercial version, as well as an open source version of it’s mail server. Currently, no Linux distributions use Zimbra as the default mail server.

The Best Linux MTA

The best Linux-based MTA for your needs can be either MTA mentioned in this article- it’s all up to your needs. For most organizations and people, Sendmail fills that role very well. If you don’t need enterprise features, or the best security record, Sendmail clearly stands out based on it’s performance and features. Exim is a close second, followed by Qmail, Zimbra, and Sendmail (in that order of preference). Qmail’s excellent security record is it’s biggest strength, and Sendmail’s popularity is quickly vanishing. In the end, the best MTA for your server depends on your needs- and your needs alone.

Christopher Pace is a linux consultant who offers a variety of linux consulting services to clients. Linux administration services are offered remotely, which helps his clients save both money and time!