Network monitoring

Optimizing UPS power use when the power goes out

Leave a Comment / Eaton, Network monitoring, nut, UPS / By /

This post is mostly for myself. I’m just putting my Sunday morning thoughts down for later review and consideration. When Selecting replacements batteries for my Eaton 5PX UPS (5PX2200RT & 5PXEBM48RT), I began to think about: when the power goes off, why can’t I keep using my laptop? Usually, I still have an Internet connection: the ISP isn’t going offline. Why not turn off the two servers in the basement, and anything else […]

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Nagios 3: moving from nrpe 3 to nrpe 4 – what needs changing?

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Yesterday, I noticed this message in one of the “daily security run output” emails which FreeBSD host can send out. I’ve used net-mgmt/nrpe3 for several years. It checks remote hosts and runs any number of predetermined commands and returns the results. It’s stable, highly configurable, and just keeps running. I had a look at the replacement (net-mgmt/nrpe) and decided to build and install it. First, it went onto my poudriere package bulding host

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Monitoring FreeBSD jails from the host

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It was May 2021 when I tweeted about monitoring FreeBSD jails which had jail IP addresses only in the 127.0.0.0/8 range. Yesterday, nearly 6 months later, I did the first test of this. This came up because I’m getting a new FreshPorts node ready. I’ve created a file in the jail to be run from the host. That script runs in the jail but it initiated by a process on the host. In

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Listen queue overflow

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The R720 is showing a message like this from time to time: Jan 1 07:42:20 r720-01 kernel: sonewconn: pcb 0xfffff835e785d5b8: Listen queue overflow: 8 already in queue awaiting acceptance (1 occurrences) Jan 1 08:02:21 r720-01 syslogd: last message repeated 1 times Jan 1 08:27:22 r720-01 kernel: sonewconn: pcb 0xfffff835e785d5b8: Listen queue overflow: 8 already in queue awaiting acceptance (2 occurrences) Jan 1 16:07:04 r720-01 kernel: sonewconn: pcb 0xfffff835e785d5b8: Listen queue overflow: 8 already

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Munin

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This is an old post I wrote, but never published, back in 2010. I’ve started using Munin for some statistical monitoring. Using the hddtemp_smartctl plugin, I was getting some permission errors. After printing the output of the command, I noticed these in the logs: 2010/03/11-18:30:05 [60845] [ERROR] Command /usr/local/sbin/smartctl -A /dev/ad8 on drive ad8 failed: 256. The plugin needs to have read permission on all monitored devices. smartctl 5.39 2009-12-09 r2995 [FreeBSD 8.0-STABLE

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Monitoring backups via Nagios and a shell script

Leave a Comment / Backups, Nagios, Network monitoring, nrpe, Open Source / By /

Backups are useless without restores. I’ve written a few posts about Nagios, my current monitoring tool of choice. Included with Nagios are a number of plugins and you can even write your own plugins. In this post, I’ll show you a shell script I wrote to make sure my backup files turn up where they should, when they should. In my case, these files are database backups, but the idea behind the script

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Wireless Diagnostics on OSX – check your wifi

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I wanted to know how many wireless access points (WAPs) were using what channels near my place. I googled and found a reference to the built-in OSX tool, Wireless Diagnostics. But to be fair, the app is hidden. To access the app, hold the Command key while clicking on the WIFI icon. This will change what usually appears: Now click on Wireless Diagnostics. The following should appear. This is the boring part. Not

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Monitoring temperature

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Earlier today, I was reminded of a old series of tweets regarding temperature. That led me to this to a FreeBSD Forums post which showed me this interesting bit of information. I draw your attention to the two hw.acpi.thermal values near the top. Those may well represent the ambient room temperature, more or less. A little shell script. Some graphing. Bob’s yer uncle. # kldload coretemp # sysctl -a | grep -i “temp”.

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ntp wasn’t running but Nagios didn’t notice

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Earlier today, I noticed the following output from a Bacula job: 24-Sep 14:14 bacula-dir JobId 38548: Start Backup JobId 38548, Job=latens_home.2010-09-24_14.12.38_31 24-Sep 14:14 bacula-dir JobId 38548: Using Device “MegaFile-latens” 24-Sep 14:09 latens-fd JobId 38548: DIR and FD clocks differ by -307 seconds, FD automatically compensating. That’s 5 minutes. It shouldn’t be varying by that much. So I started ntp. That’s when I noticed it was not being started by /etc/rc.conf. But I thought

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NRPE: Unable to read output

1 Comment / Nagios, Network monitoring, Open Source / By /

After rebooting kraken to take a photo, I found nagios was displaying an error for my smartmon checks: NRPE: Unable to read output. Running the command by hand on the nagios server, I found: $ /usr/local/libexec/nagios/check_nrpe2 -H kraken -c check_smartmon_ad24 NRPE: Unable to read output But from the remote server I got: # /usr/local/libexec/nagios/check_smartmon -d /dev/ad24 OK: device is functional and stable (temperature: 29) I restarted npre and the problem went away… not

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