LHS Episode #072: We Need Cache

by Black Sparrow Media Episode #72 Duration: 01:19:39
LHS Episode #072: We Need Cache

Welcome to another fine and dandy episode of Linux in the Ham Shack. The end of 2011 and the beginning of 2012 have been very busy for your stalwart co-hosts, but we press on. Shows are being recorded, content is being disseminated and our listeners are being educated--sort of. We hope everyone has had a wonderful start to the new year and best of luck in all your endeavors, present and future. Oh, and if you find a free moment or two, please tell a friend about LHS. The publicity will do us all good.

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Introduction:

  • Happy New Year! Sorry for the delay in releasing the last several episodes.

Announcements:

Thanks for the information, Leif. Our advice is to pick the story you like and stick with it! 🙂

Topics:

  • Channel Bonding for Linux

  • Channel bonding combines two or more network interfaces on a host computer for redundancy or greater bandwidth.

  • By bonding two or more Ethernet links to your computer, you get several benefits, including redundancy, so if one network port fails, the other still works, and greater bandwidth when both (or more) links are running.

  • Based on the Link Aggregation Control Protocol (LACP), though called different things depending on vendor, such as EtherChannel or PortChannel.

  • It’s relatively easy to set up. Briefly:

  • You’ll need an Ethernet port for each link, set up and configured in the normal manner. These ports will likely be called eth0, eth1, etc.

  • Install the ifenslave package, which allows you to create a “bond” interface, say bond0.

  • Create modules.conf file to alias the various ethx devices as bonding interfaces.

  • Modify your /etc/sysconfig or /etc/network/interfaces file (depending on your version of Linux) to include an entry that references the bond0 interface.

  • ifup the bond0 interface, and all the component interfaces should come up.

  • Other configuration settings will set up the failover time.

  • Resources:

  • https://www.linux-corner.info/bonding.html for Red Hat-based systems.

  • https://wiki.debian.org/Bonding for Debian-based systems.

  • Ethernet bonding on linux (Debian based)

  • Ethernet Bonding Configuration in Debian

  • Bonding

  • Our hosts then discuss the utility of load balancing between multiple network interfaces.

  • More about the apt-cache utility

  • Russ provides more information about the apt-cache utility for Debian-based systems, previously discussed in Episode 69.

  • The basic syntax of the utility is apt-cache [command] [package(s)]. There are many commands you can use, including:

  • policy [package] shows which repository provided, or would provide, a specified package.

  • depends [package] shows all packages in the repositories that depend on the named package, and which other packages would be installed or suggested.

  • showpkg [package] shows reversed dependencies; that is, which packages depend on the named package, and the MD5 checksum of the package.

  • stats  shows some aggregate sums about all the packages in the repositories included on your system. For example, on Russ’ system: Total package names: 42814 (856 k) Total package structures: 42814 (2,398 k) Normal packages: 32874 Pure virtual packages: 374 Single virtual packages: 3670 Mixed virtual packages: 465 Missing: 5431 Total distinct versions: 33706 (2,427 k) Total distinct descriptions: 33706 (809 k) Total dependencies: 200360 (5,610 k) Total ver/file relations: 35248 (846 k) Total Desc/File relations: 33706 (809 k) Total Provides mappings: 6402 (128 k) Total globbed strings: 197 (2,192 ) Total dependency version space: 789 k Total slack space: 65.4 k Total space accounted for: 11.5 M

  • unmet shows packages in the repositories with unmet dependencies in the tree, that is, if you attempted to install, would fail.

  • show [package] shows meta information about the package. For example, “apt-cache show adduser” returns: Package: adduser Version: 3.113 Installed-Size: 1100 Maintainer: Debian Adduser Developers Architecture: all Replaces: manpages-it (« 0.3.4-2), manpages-pl (= 5.6.0) Suggests: liblocale-gettext-perl, perl-modules Description: add and remove users and groups This package includes the ‘adduser’ and ‘deluser’ commands for creating and removing users. - ‘adduser’ creates new users and groups and adds existing users to existing groups; - ‘deluser’ removes users and groups and removes users from a given group. Adding users with ‘adduser’ is much easier than adding them manually. Adduser will choose appropriate UID and GID values, create a home directory, copy skeletal user configuration, and automate setting initial values for the user’s password, real name and so on. Deluser can back up and remove users’ home directories and mail spool or all the files they own on the system. A custom script can be executed after each of the commands. Development mailing list: https://lists.alioth.debian.org/mailman/listinfo/adduser-devel/ Homepage: https://alioth.debian.org/projects/adduser/ Tag: admin::user-management, implemented-in::perl, interface:: Section: admin Priority: important Filename: pool/main/a/adduser/adduser_3.113_all.deb Size: 217556 MD5sum: 74c114db96f321f4d097b04ae305600a SHA1: 567b8e42dc9b4777ab694f15ca71b7fa159749ef SHA256: 3bfea7f2ffcb363e2cc2b701a6e6d2079f7554b4d76194a118916afd2400f5c4

  • Tim Allen’s character in his latest TV show, “Last Man Standing” is a Ham Radio Operator, KA0XTT.

Feedback:

  • Kevin, KC9VAN, writes that he’s enjoying the show and just recently received his ham radio license. He also notes that he’s had the most luck with Hewlett-Packard printers under Linux. Thanks, Kevin. Russ has had good luck with Dell printers and generic PCL drivers.

  • Leif, KC8RWR, posted several comments about episode 67. He suggests avoiding “all-in-one” printers, and instead, using separate printers and scanners. (I agree! -Ed.) Often, used scanners can be had for very little money. Leif also suggests buying printers with separate cartridges for each color. That way, you’re not throwing away all the colors when just one is empty. He seconds Russ’ suggestion to use a laser printer over inkjet, as the cost per page is less.

  • Russ likes the Epson Artisan 835, especially for printing on CDs and DVDs, and it works well with Linux.

Contact Info:

Music:

  • To be added.