Musings on technology, management, and everything in between.

Archive for November, 2009

Recording disk statistics with sysstat on RHEL/CentOS

Unlike on Debian-like systems, the default configuration for sysstat’s sa1 collector on RHEL/CentOS does not include disk statistics (like you would get from iostat) in the sa collection output. This is due to a missing flag in the cron.d fragment that calls sa1. The “-A” flag to sa1 defies...

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Interesting links for 11/25/2009

With all the busy-ness that this holiday weekend entails, I’m just going to leave you all with a bunch of links: TaoSecurity has a really interesting writeup about the ethics of Shodan, a “computer search engine” which provides some very interesting tools for people trying to secure their systems...

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Nagios plugin: check_sa.pl

There’s a lot of useful Nagios addons out there. One of them, pnp4nagios, allows you to create graphs of all of your Nagios performance data with zero configuration. This is pretty nice, because your monitoring configurations are kept in one place, rather than having to separately maintain configurations for...

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Fedora 12 allows users to install signed packages…

Update: According to a post on lwn that I can’t find at the moment, they’ve already reverted this decision with a subsequent update. It should be resolved soon. …without root privileges, without authenticating. Yeah, you read that right. SANS has the writeup: A “bug” created back in November against...

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44% of security products contain security problems

Slashdot linked to an interesting analysis of an ISCA Labs report, done by Help Net Security, about the underperformance of various network security products. The meat of the analysis focused on how most products fail to achieve certification on the first test, but I found this particular statistic incredibly...

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More on CentOS 5.3 to 5.4

So, here’s a humbling, humiliating and slightly funny follow-up to my last blog post: I’ve always done my due diligence in making sure upgrades go smoothly. As a result, I have a habit of tirelessly poring over release notes and the “known issues” section therein. However, I got burned...

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CentOS 5.3 to 5.4 upgrade woes

I’ve been pushing out CentOS 5.4 on a number of test systems this week, and I came upon a very interesting, very insidious, and very annoying problem. When running the upgrade, yum upgrade seems to run without a hitch, and returns completely successfully with no errors or warnings. However,...

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How (not) to interview technical candidates

First, my sincerest apologies for the length of this one. I usually don’t spit out this much at once. Technical interviews are hard. Really, really hard. This is why a lot of big corporations continue to hire IT employees on a six-month contract, followed by an offer for continued...

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Ransomware gets smarter

El Reg writes: Devious virus writers have come up with a new twist on ransomware-style malware. A new strain of Trojan encrypts recently-opened files on compromised Windows PCs. But instead of demanding a ransom for a decryption key to unlock files, the malware relies on users to search the...

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ZFS Inline Deduplication

Those of you who have been following the lists, the bug trackers or Planet OpenSolaris know this already, but for the rest of you, Sun’s ZFS filesystem has just seen inline dedupe support merged into OpenSolaris trunk, presumably to be appearing in the next major OS release. Jeff Bonwick...

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