Best of Technical Support
I want to delete a user account. But I can't find any command to do so. Is there any utility to do so? —Harry Wong
Many of the Linux distributions ship with a deluser or userdel command that reverses the action of the adduser or useradd command. Search the man pages or simply try the commands to see if they exist on your system.
Failing that, deleting a user consists of two main steps:
1) Delete the user's entry in /etc/passwd
As root, and using your favorite editor, edit /etc/passwd (I always make a backup copy before messing with the password file because you can never be too careful). Search for the line that starts with the users login ID and delete the entire line.
2) Delete the user's home directory.
Again as root, use the rm command recursively to get rid of files by typing —Vince Waldon email@example.com
I have just added four additional drives to my Linux/Compaq Proliant 1000. I recompiled the kernel to include the md/linear option. Now I cannot find any instructions on how to make the MD work with all the drives. What I want to do is have all five drives connected such that when the first drive is full, the data will go to the second drive and so on. —Robert Binz
More information on using MD can be found in the MD FAQ at ftp://sweet-smoke.ufr-info-p7.ibp.fr/pub/linux/. You should find two files. The first, md-FAQ, can answer many of your questions. The second, md035.tar.gz (this is the current version of MD at the time of this writing), contains the utilities you will need to manage your MD system, as well as more documentation.
Be aware the MD package is still under development. Certain parts of the system (such as mirroring) are not yet considered stable. If you plan to use MD, I recommend you join the mailing list by sending mail to firstname.lastname@example.org with the message body “subscribe linux-raid”. —Chad Robinson, BRT Technical Services Corporation email@example.com
I need to create a captive account which restricts the user to only FTP access of the system. I also need to restrict the user to accessing only directories above a root directory I specify. Can you please let me know how to implement this? —Steve Stuczynski
First add a guest group entry in the /etc/ftpaccess file. Specify which group of users will be treated as guests by typing guestgroup ftponly. Then create the ftponly entry in /etc/group by typing ftponly::22:. Next, create a user member of this group, with no shell, in /etc/passwd:
user1:the_passwd:22:22:Limited FTP user:/home/ftp/user1:/bin/true
Don't forget to create the /home/ftp/user1 directory. Last, add /bin/true in /etc/shells. Now check your work to make sure it works! —Pierre Ficheaux, Lectra Systemes firstname.lastname@example.org
There are simple and complex ways to restrict user access to FTP only. There is a HOWTO that describes this in detail, as well as potential security problems you should be aware of.
This FAQ is unfortunately not an official part of the Linux HOWTO and mini-HOWTO compilation, but Slackware users can find it as part of the installation anyway, in /usr/doc/faq/howto/mini/Anon-FTP-FAQ. Although the document is geared primarily towards creating a secure anonymous FTP site, it actually covers an extensive range of the setup required for your desired effect. —Chad Robinson, BRT Technical Services Corporation email@example.com
After a successful installation of Red Hat's Colgate release of Linux, I have found I would like to change some of my configuration settings. Is there a way to get back into the setup utility that steps you through setup? Or is there an easier way of doing this? In particular, my NIC is not working right and I don't know how to configure it correctly. —Jeff L. LaPlante
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide