A couple of months ago I setup a cron job to automatically create timestamped snapshots of my zfs filesystem. Little did I know, there was a syntax error preventing my job from actually executing. Here’s the correct (yet not-so-intuitive) cron job to get a nightly, timestamped snapshot of the ZFS filesystem @tank@:
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Featured Articles           So, I got into a discussion with a friend of mine in my Computer Security class at UCF about this script. I’m posting this for historical and educational purposes only. As always, I never condone the implementation of any of my content for malicious intent. Moreover, this script has flaws that * would make it useless in such a scenario. Don’t do it! Here’s a script I hacked up last semester when I was playing with MITM attacks and packet eavesdropping with ettercap:. This scripts will automatically: fake its MAC Address get a new IP Address collect a list of hosts on the same subnet as itself iterate through and ARP poison: each of these hosts one at a time for 5 minutes each save all data collected in host-specific files in a timestamped directory repeat until the hard drive is full I really should be studying for my stat exam tomorrow, but I was logging into my.ucf to download my lecture notes, and while Blackboard Learning System (the really shitty replacement for WebCT) was stuck in an infinite loading loop (most probably caused by incompetent javascript) I decided to finally get Google Chromium (which apparently has an excellent javascript engine) working on my Sabayon Linux desktop. Quite often, and for whatever reason, I go to play a sound in linux and I get a “device or resource busy” error. Restarting alsasound doesn’t work. Here’s what does: guttersnipe@guttersnipe ~ $ fuser -v /dev/snd/* USER PID ACCESS COMMAND /dev/snd/controlC0: guttersnipe 21993 F…. python2.5 /dev/snd/pcmC0D0p: guttersnipe 21993 F…. python2.5 /dev/snd/timer: guttersnipe 21993 f…. python2.5 guttersnipe@guttersnipe ~ $ lsof -n | grep "/dev/snd" python2.5 21993 guttersnipe 78r CHR 116,2 0t0 10272 /dev/snd/timer python2.5 21993 guttersnipe 79u CHR 116,4 0t0 10476 /dev/snd/pcmC0D0p python2.5 21993 guttersnipe 80u CHR 116,7 0t0 10466 /dev/snd/controlC0 guttersnipe@guttersnipe ~ $ kill 21993 Source: http://alsa.opensrc.org/index.php/FAQ#How_can_I_find_which_processes_are_using_Alsa_devices.3F I bought a cheap, $30 refurbished MP3 player off of woot back in December ’08: the I recently setup a cheap terrabyte server with an old Dell 2450, 3 1TB Hitachi drives, and this cheap MnssCool XWT-RC040 4-port Sata ‘high speed’ PCI Controller Card. The best thing about this card was that it was cheap. I got it for $30 off of newegg. The worst part was that it pretty much comes broken. You have to flash the bios to make it work well. So, xen is really beginning to piss me off. I turned off all my machines to do a snapshot, and when I tried to bring them back up, they were all in the ‘blocked’ state. Upon further investigation (using virt-manager/xm console), I found that they were hung at the “Checking for hardware changes” item in their boot process. This could be a CentOS/RHEL 5 issue, but I’m putting my money on xen. 
I’ve been playing around with SELinux at work recently. Not surprisingly, I was struggling to get SELINUXTYPE=strict to work properly. Unfortunately, all “google results for ‘enabling selinux strict’ would return were dead ends. People would enable selinux strict, kernel panic, and ‘fix’ it by disabling selinux. Well, a co-worker of mine *was* able to successfully enable selinux’s strict policy on RHEL5 (CentOS 5). He gave me this guide to post to the world for others to see how (thanks Mykola): Storage is getting so cheap these days. So cheap, in fact, that multi-terabyte home servers are now economically feasible. The emergence of cheap 1 terabye hard drives and ZFS perfectly compliment each other. Like others, I’ve embraced these two technologies to build myself a redundant, multi-TB disk array with 3x1TB drives running in a RAIDZ on OpenSolaris for about $300. Debian If you want to be able to compile packages in debain/ubunutu, you can issue the following command: apt-get install build-essential
Red Hat If you want to be able to compile packages in red hat/centos, you can issue the following command: yum install make gcc gcc-c++ kernel-devel …or, if you don’t care about maintaining a small footprint, you can get *all* of the development packages (including X devs–eww): yum groupinstall "Development Tools"
Open Solaris If you want to be able to compile packages in open solaris, you can issue the following command: pkg install SUNWgcc |
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