Under CentOS Linux it is possible to lock out a user login after failed login attempts. This is a security feature. You can also automatically unlock account after some time.
pam_tally – login counter (tallying) module
This module maintains a count of attempted accesses, can reset count on success, can deny access if too many attempts fail.
Use /etc/pam.d/system-auth configuration file to configure attempted login accesses and other related activities. Append following AUTH configuration to /etc/pam.d/system-auth file:
auth required pam_tally.so onerr=fail deny=5 unlock_time=21600
(a)deny=5 – Deny access if tally for this user exceeds 5 times.
(b) unlock_time=21600 – Allow access after 21600 seconds (6 hours) after failed attempt. If this option is used the user will be locked out for the specified amount of time after he exceeded his maximum allowed attempts. Otherwise the account is locked until the lock is removed by a manual intervention of the system administrator.
(c) onerr=fail – If something weird happens (like unable to open the file), return with PAM_SUCESS if onerr=succeed is given, else with the corresponding PAM error code.
Default file /var/log/faillog is used to keep login counts.
The above PAM module is part of all Linux distribution and configuration should work with any Linux distribution.
Sysadmin because even developers need heroes!!!
- man pages faillog, pam.conf, pam.d, pam, and pam_tally
- pam_tally – login counter (tallying) module documentation.
- CentOS Linux project
This small guide may come handy…
From the article:
One great thing about Linux is that you can transplant a hard disk from a machine that runs a 32-bit AMD XP processor into a new 64-bit Intel Core 2 machine, and the Linux installation will continue to work. However, if you do this, you’ll be running a 32-bit kernel, a C library, and a complete system install on a processor that could happily run 64-bit code. You’ll waste even more resources if your new machine has 4GB or more of system memory, and you’ll be forced to either not use some of it or run a 32-bit Physical Address Extension (PAE) kernel. Cross-grading to the 64-bit variant of your Linux distribution can help you use your resources more wisely. A disclaimer: changing the architecture of your Fedora installation from 32 to 64-bit isn’t recommended or supported in any way. Perform this at your own risk after creating a suitable backup.
=> Upgrade from 32-bit to 64-bit Fedora Linux without a system reinstall [linux.com]
Asterisk PBX (private branch exchange) is an open source telephone system. Like any PBX, it allows a number of attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network (PSTN).
Setting up Asterisk is considered as a difficult task. Building a VoIP Linux server with Asterisk is easy with AsteriskNOW software, which can setup Asterisk in minutes:
AsteriskNOW is an open source Software Appliance; a customized Linux distribution that includes Asterisk (the leading open source telephony engine and tool kit), the AsteriskGUI, and all other software needed for an Asterisk system. AsteriskNOW is easy to install, and offers flexibility, functionality and features not available in advanced, high-cost proprietary business systems.
Overall I’m quite impressed with this project as it provides:
=> Ease of use
=> Ease of installation
=> GUI Wizards
=> Open source project
==> Visit official AsteriskNow project home page.
Vixta.org is a Fedora-based Linux distribution designed to be user-friendly and eye-catching, similar in look and feel to Windows Vista. Trying to spread Linux to the “masses”, not just sysadmins. It is vista look-a-like Linux Os. If you like Vista user interface, this distro is for you.
Vixta Linux distribution Goals
1. Absolutely free
2. Spread linux to the “masses”.
3. ABN – AbsolutelyNo Config.
6. Familiar look and Feel
Download Vixta Linux distribution
=> Visit official project home page
Microsoft claims the latest Free Software GPL v3 release has no effect on any of its Linux distribution deals. Microsoft cleared the air July 5 on its obligations to GNU General Public License Version 3 support, declaring it will not provide support or updates for GPLv3 under the deal it penned in November with Novell to administer certificates for the Linux distribution.
Microsoft also said July 5 that its agreement with Novell, as well as those with Linux rivals Xandros and Linspire, were unaffected by the release June 29 of GPLv3 by the Free Software Foundation.
Microsoft Says It Is Not Bound by GPLv3
Slackware was my first Linux distribution. Slackware version 12.0 has been released. It has many improvements as compare to old version. Slackware was one of the earliest distributions, and the oldest currently being maintained. Slackware has a reputation of stable releases of applications, standing mainly for design for stability and simplicity.
From the announcement:
This first Slackware edition of the year combines Slackware’s legendary simplicity (and close tracking of original sources), stability, and
security with some of the latest advances in Linux technology. Expect no less than the best Slackware yet. Among the many program updates and distribution enhancements, you’ll find two of the most advanced desktop environments available today: Xfce 4.4.1, a fast and lightweight but visually appealing and easy to use desktop environment, and KDE 3.5.7, the latest version of the award-winning K Desktop Environment. We have added to Slackware support for HAL (the Hardware Abstraction Layer) which allows the system administrator to add users to the cdrom and plugdev groups. Then they will be able to use items such as USB flash sticks, USB cameras that appear like USB storage, portable hard drives, CD and DVD media, MP3 players, and more, all without requiring sudo, the mount or umount command. Just plug and play. Properly set up, Slackware’s desktop should be suitable for any level of Linux experience.
Download link – ( Download Slackware Linux )
The full version of Slackware Linux 12.0 is available for download from the central Slackware FTP sites:
If the sites are busy, see the list of official mirror sites here. Slackware team will be setting up BitTorrent downloads for the official ISO images soon.
Almost all new Linux wanna be guru (read as users who want to switch to Linux) asks a question:
I want to switch to Linux completely from Windows XP SP2. Which Linux version will be best – Redhat, SuSE, or other? I use my PC for:
Watching DVD / MP3
Iâ€™m also willing to spend a small amount of money if required to purchase Linux version.
Short answer is none. I canâ€™t suggest *distro* name.
Linux is all about choice and freedom. There are different Linux distribution exists with different goals. It is good idea to define your goals and select Linux distribution as per your requirements.
I like Redhat and Debian for server as they are rock solid stable and comes with good binary packaging system. Some will swear up by Knoppix Live CD.
Some people like Suse and other recommends Ubuntu. There are others who like to compile everything from scratch (Gentoo).
- Consider following factors while selecting Linux:
I recommend that you try out at least some different distributions. Go to distrowatch.com and look out What’s Hot and What’s NotMake sure your hardware is compatible with Linux. Download Live CD (list of all Live CD) and see if your hardware is compatible with Linux.Make sure good community support exists for your distro (for example check out Ubuntu community support forum)Get a good Linux book that teaches basis of LinuxLearn how to use search engine to find out solution to the problemsLearn to read man pages effectively and Linux commands to help you navigateContact your nearest Linux user group (LUG) and see what other members recommendsAsk a questions whenever in doubt, join Linux mailing lists and forums. When posting questions to a forum / newsgroup it is good idea to format the question and it’s content in a proper way in order to get a good answer. Make sure you provide all information while posting a question. (See more guideline – how to ask questions the smart way)Finally you can always donate a small amount of money to your favorite distro and/or to any other open source project.
- Your Linux skill level
- Linux as server / network admin workstation
- Running Linux on a new Hardware / Laptop
- Running Linux on an older machine (486/PI/PII/Celeron)
- Multilingual support (Hindi / Japanese language user interface)
- Running Linux on Office PC for email and office work
- Community support
- Commercial support
Surely, there are dozens of other reasons to select specific distro, so please do share your views and suggestions :D