I have been using Webmin for a couple years now to administer my servers. It is a wonderful and powerful tool. I was very pleased to read about it in your December 2001 issue (“Webmin: Good for Guru and Newbie Alike”). Mr. Elmendorf did a great job. I hope to hear more on Webmin in the future in the pages of LJ. Like, how to add modules and such. Great work!
—Jody “JoLinux” Harvey
Thanks so very much for your article “Taming the Wild Netfilter” in Linux Journal (September 2001) regarding iptables. I've been banging my head on a wall to come up with a clean solution for protecting my home network from internet kiddies. Your script (with some modification) is a pleasure to work with. All I had to do is add some accepts for a couple of ports on the Linux box and voilà! Your tutorial is excellent!
This comment is a little frivolous, but still worth an e-mail. At the end of his article “Mainstream Linux”, December 2001 issue of LJ, Robin Rowe quotes Linus as saying, “Software is like sex: it's better when it's free.” I read the quote to my wife and her immediate reaction went something like this: “How does he know? If what he says is true, then he must have paid for it sometime in his past!” Whoops! Choose your words carefully, Linus!
While Editor in Chief Richard Vernon has every right to support the Electronic Frontier Foundation and to encourage his readers to do the same, he should be more forthcoming about the positions taken by the Foundation [see “EEF Wants You”, December 2001 issue of LJ]. The Foundation is about more than protecting open-source programming. It is also about preventing public libraries from filtering web content for children and allowing crackers to freely distribute the means to steal proprietary programming in the name of free speech. Before joining or contributing, I would urge readers to examine the positions of the Foundation and the writings of its cofounder, John Perry Barlow, by visiting its web site. Love the magazine, otherwise.
What exactly does “the means to steal proprietary programming” mean? A tool that lets you view DVDs on Linux? A debugger? If anything that can be used to infringe copyright should be banned, then we have no Linux left. We too urge readers to examine the Foundation's positions by visiting its web site (www.eff.org)--the more they read about the EFF, the better.
After reading your last two articles in Linux Journal on using JBoss [see Reuven Lerner's December 2001 and January 2002 At the Forge column], I just have to say, “excellent job!” Your articles are really a pleasure to read, and I've passed them along to other developers here as well as our director, and they agree. We're starting to consider how to get JBoss accepted here as an approved platform for Kaiser Permanente Hospitals (Kaiser has about 110,000 employees here in the United States). I'm greatly looking forward to your treatment of Zope. Keep up the superb work!
I was pleased to see the review of the HP SureStore Ultrium 230 tape drive in the December 2001 issue. The company that I work for currently is considering Qualstar TLS tape libraries for use on our data collection platforms. After reading the article, it appears that this might not be such a good idea. I was wondering if anyone has had any experience using robotic tape libraries on moving platforms such as ships or aircraft?
We have successfully deployed HP SureStore Ultrium 230 tape drives on our ships and are extremely happy with their performance. The “Open” part of LTO is what originally drew us to this drive. With multiple vendors for both the drives and the media, the prices should prove to be competitive. The price for the media has already come down significantly from launch. We tested a RAIDZONE RS-15 1TB NAS with a directly attached HP SureStore Ultrium 230 tape drive. The actual throughput we got was 13MB/sec using GNU tar. This works out to about 46GB/hour (pretty close to the advertised rate). The NAS had no problem supplying the data to the drive. In fact, it was coasting most of the time.
—Jan “Evil Twin” Depner
With regards to the query “128-Bit Precision with GCC” in the Best of Tech column of the December 2001 issue, the reply was neither correct nor helpful—GMP is not the equivalent and using GMP means rewriting code. Some compilers, AIX amongst them, will carry out calculations using 64 bits (or 128 bits, depending on the processor) with the appropriate option. (Using this, means that the product of two 32-bit numbers will always fit within an int. No code modification is needed.) GMP, however, is a multi-precision package that defines certain data structures wherein the multi-precision numbers are put. To use it, you must extensively rewrite your code. Some compilers, including gcc, accept the “long long” extension and use 64 bits for calculation but that still requires modifying your code and raises portability questions. My answer would be that, sadly, there is no equivalent without some sort of code modification. Such an option to gcc would be nice, though.
Upon rereading my letter [above], I realized that it reads far harsher than I intended. Both the column and the individual answering the query have done your readers good service in the past. I did not mean to slight either, and I apologise if anyone took amiss. I merely wished to indicate that the solution is by no means simple.