< ^ txt
Mon Dec 7 08:30:36 EST 2015
Went to bed at eleven, slept well, and woke up before seven.
Mostly cloudy with a high of forty today.
Goals:
Work:
- Check out nfsen
http://nfsen.sourceforge.net/
Nope.
- Work on new firefly vm
Done.
Twenty minute walk at lunch. Not too cold. A little hazy. No birds.
Hmm. Jason never called me today.
Home:
- Set up data zpool on blinky
Done.
- Schedule monthly zfs scrubs
Done?
I set 'daily_scrub_zfs_enable="YES"'. See periodic.conf(5).
- Configure ipfw on blinky
- Make sure TRIM is on
https://www.freebsd.org/doc/faq/all-about-zfs.html#idp59588304
"ZFS TRIM is enabled by default"
- Figure out backups for blinky
- Does bsd not have .toprc? Just command line switches?
It doesn't appear to use .toprc.
- Set up (backup) IP updater script
Done.
Need to verify that it actually runs.
Yes, it runs.
- Generate ssh keys on blinky
Done.
`ssh-keygen -t rsa -b 4096 -C "paulgorman@blinky.devilghost.com"`
- Find a dynamic dns client
Done.
/usr/ports/dns/ddclient/
https://www.namecheap.com/support/knowledgebase/article.aspx/583
Installed and configured.
I started a run book for blinky:
http://paulgorman.org/technical/freebsd-blinky-runbook.txt
I also created a dedicated L2ARC on the third SSD.
Questions:
- How to stop `man` from "falling off the end"?
Oh, right. I forgot to set my pager to `less`.
- How does gigabit POE work if POE used a pair for power?
http://www.blackbox.com/Store/Results.aspx/Networking/PoE/n-4294953056
The answer is through the use of phantom power—power sent over the same wire pairs used for data. When the same pair is used for both power and data, the power and data transmissions don’t interfere with each other. Because electricity and data function at opposite ends of the frequency spectrum, they can travel over the same cable. Electricity has a low frequency of 60 Hz or less, and data transmissions have frequencies that can range from 10 million to 100 million Hz.
10- and 100-Mbps PoE may also use phantom power. The 802.3af PoE standard for use with 10BASE-T and 100BASE-TX defines two methods of power transmission. In one method, called Alternative A, power and data are sent over the same pair. In the other method, called Alternative B, two wire pairs are used to transmit data, and the remaining two pairs are used for power. That there are two different PoE power-transmission schemes isn’t obvious to the casual user because PoE Powered Devices (PDs) are made to accept power in either format.
< ^ txt