linux Archive

Skeletons: Older versions of ntp and not using DNS

A while ago (years), I reluctantly set up ntp on some servers using an IP address for the source server; at the time, using a DNS name in ntp.conf was incompatible with the ntp/ntpd version and I didn't want to go out of my way to compile it from scratch. Today,...
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MySQL’s max_connect_errors … 6 years later…

Having recently been bitten by the awful default value (10) for max_connect_errors on a production server - I'm having a very hard time coming to terms with who the heck thought this would be a good way to do it. This type of "feature" allows you to effecitvely DOS yourself quickly...
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Using Logstash to log SMTP/email bounces like a boss

I've recently worked on a customized emailing suite for a client that involves bulk email (shutter) and thought I'd do a write up on a few things that I thought were slick. Originally we decided to use AWS SES but were quickly kicked off of the service because my client doesn't...
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MySQL command line – zebra stripe admin tool

I came up with a cool usage for the zebra stripe admin tool.  In MySQL you can set a custom pager for your MySQL CLI output; so one can simply set it to the zebra stripe tool and get the benefit of alternated rows for better visual clarity. Something like 'PAGER...
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Re: Linux and hardware support – specifically Graphics and lack thereof

The passion here says enough: (Linus gives NVidia a what for) Edit: Apparently embedded view won't handle the timestamp I used - skip to 49m 10s http://www.youtube.com/watch?v=MShbP3OpASA&t49m10s...
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Disable PHP 5.4’s built-in web server, while keeping CLI …

Administrators: Don't get blind-sided by PHP 5.4's CLI web server!I've gone over a similar issue like this before regarding the likes of git/hg. While those are developer tools and are less likely to be present on a production machine.PHP 5.4 is jumping on the bandwagon to include a 'cute' little...
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/bin/false – Report false bugs to …

While sifting through the manpages for /bin/false (looking for crafty uses for this oddball command) - I just had to share a funny line from within the manpage:[crayon-5b784d450040d835262287/]Maybe it's been a long day =| Subscribe in a reader...
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ab – Apache Bench, understanding and getting tangible results.

Apache Bench (AB) is a very powerful tool when used right. I use it as a guideline for how to set up my apache2/httpd.conf files. All too often I see people boasting that they can get an outrageous number of RPS in AB (the Apace Bench tool). "OMG, I totally get 3,000...
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Grepping extremely large files

So you forgot to set up logrotate on an active log eh? You've got a many gigabyte file to weed through and you need to extract a chunk of time from it?Here's a quick cheat sheet to help you get by, quickly and sanely.It's about byte offsets!Get the byte offset...
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The inherent risks of ‘daemonize’ features in developer tools – Git, Mercurial (hg)

A handful of tools such as mercurial, git, (soon PHP - which chances are will be it's own binary) have their own 'daemonize' functionality.Whatever your reasons - if you want to disable these; there's little to no help in figuring out how... til now...If you want to disable Mercurial's hg...
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Kernel.org, linux.com down, still… also, Git! – Updated!

With news breaking about the compromised systems for kernel.org, linux.com, which are sites are "down for maintenance". Completely - and it's been this way for many days now. (Kernel.org since the 28th)I think it's safe to say the range and scope of the issues are pretty disappointing - the longer these...
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System admin ‘helper’: Zebra stripe log / console output

Looking at an ASCII data table can be difficult - so to start a small trip into Perl programming - I tossed together a simple Perl script, with no module requirements - zebra.pl as I call it, and it zebra stripes the output. It adds a nice touch to say...
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/usr/bin/chage – Sending emails when a pasword expires, or is about to

There's a lot of scripts out there that do this but they either don't revolve around /etc/shadow enough or they're sloppy.Here's my spin on a script for nightly cron that will parse /etc/shadow and send out emails based on the per-user values. It's resistant to garbage dates (99999 'expiration' dates)....
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MySQL 5.5.12 – init script warning

I've just reported a bug regarding the init script that comes in MySQL 5.5's source distribution .Basically, if you call the 'start' clause of the script twice it will hose the service by allowing multiple instances to run trying to utilize the same resources (pid file, socket and tcp port)...
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libflashplayer.so – quickie for install.

Need a place to put it on debian/ubuntu?[crayon-5b784d45014dd346646621/]Chromium:[crayon-5b784d45014e3217999400/]Chrome: (You might have to create the 'plugins' dir - I did =\ )[crayon-5b784d45014e5725046920/]Firefox:[crayon-5b784d45014e7712652533/]Restart all instances of the browser/s and check it out.PS: Flash on 64-bit linux doesn't matter, you can put it in lib64/ if you -REALLY- want.. Subscribe in a reader...
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Another rant on cutesy

Codenames for releases are ok.But the countless cutesy names for *nix tools get tiring ... (And don't help their adoption).  From an email from debian security list today:"Several vulnerabilities have been found in the Iceape internet suite, anunbranded version of Seamonkey:"Imagine if these tools were used in a corporate environment...
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Cacti – DNS response time

When you google for a cacti template for DNS response time, there's not a whole lot out there, and what is; is pretty out dated or involves too much fidgetry.This post assumes you're comfortable with cacti - you should be able to at least initialize a graph and fill one...
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On top – Worthy of distribution

No really, this post is about top. I've always fancied myself well versed in top; every once and a while I need a reminder. Here's a pretty cool/well presented in-depth rundown on how powerful this utility really is for people in charge of inspecting system behavior.View in HD here!Some more...
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Funny break

Best strip ever:VIA: http://xkcd.com/838/ Subscribe in a reader...
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On: ntp, ntpd. link dump!

So, in order to quickly have a (debian) machine up and running on ntp, you're bound to do something like this 'apt-get install ntp ntpdate'.The problem is that this installs 'ntpd' too. The default configuration is to allow your server to answer to NTP queries from anywhere.If you want to...
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