Gentoo Monthly Newsletter: 30 September 2008

1.  Introduction

This month in the GMN

Welcome to the September issue of the Gentoo monthly newsletter!

As usual, you can discuss any aspect of this issue of the GMN in the corresponding forum thread. We look forward to hearing from you!

2.  Gentoo News

TeTex deprecated

The TeX distribution teTeX has been obsoleted as the author has no time to maintain it anymore. However, there is a complete distribution on top of it, that is now the successor: TeXLive. Many Linux distributions have already adopted it as their standard, and it's now the TeX flavor of choice for Gentoo, as well.

You are encouraged to emerge --unmerge tetex and then emerge world to get to an up-to-date system with a modern TeX version. Please read the TeXLive migration guide for more detailed instructions.

Gentoo's TeX maintainers have also created a poll in the forums on which TeX distribution you're using. Please vote, and let them know!

Release strategy changes

As you've probably read by now, there are some planned changes in Gentoo's release strategy. We're looking to do automated weekly builds of the stages and minimal CDs, with a possible once-a-year or so update to the networkless media (Installer LiveCDs/DVDs and Universal/Package CDs). Please read the announcement for more details; there's a lot of work involved to get the process going, and we need the help!

Trustees Meeting Summary

The Gentoo Trustees held its monthly meeting on September 14, 2008. The agenda is available here.

Council Meeting Summary

The Gentoo Council held its monthly meeting on September 11, 2008. The items put up for discussion were:

• Filling the empty slot: as council member Diego Elio Pettenò retired from the council for medical reasons, Doug Goldstein has replaced him. cardoe was the next person from the original voting rankings.
• PMS as a draft standard of EAPI 0: the council voted on whether to approve PMS as a draft standard of EAPI 0. Result: approved, with acceptance conditional upon resolution of the requirements outlined by the council.

The Council met again on September 25, 2008. The items put up for discussion were:

• EAPI-2: the new EAPI is approved. This brings features such as USE dependencies to Portage; for example, a package can now directly depend on a package built with USE="foo" without resorting to trickery or "built_with_use || die" hacks.
• PROPERTIES in cache: Since using PROPERTIES in the cache is related to the EAPI, this issue should be settled among package manager developers, and only present it to the council if they cannot agree on a solution. The PM developers agreed on adding PROPERTIES to the cache as a value that the package managers can ignore.
• PROPERTIES=interactive in ebuilds: This is a retroactive, backwards-compatible EAPI change that council approved. It allows ebuilds to set a variable stating up-front that they require user interaction, such as agreeing to a license or inputting information.

Coming Up

• Bugday: Looking for a way to help out Gentoo without investing a lot of time? Join us on October 04 for our monthly bugday, and help us squash some bugs.
• Council Meeting: The Gentoo Council meets twice every month to discuss important technical issues that affect Gentoo as a whole. The next meeting is scheduled to be held on October 09, and everyone is welcome to participate - #gentoo-council on irc.freenode.net at 2000UTC.
• Trustees Meeting: Scheduled for October 19.

3.  Heard in the Community

Gentoo-Quebec training

The Gentoo-Quebec group has offered its first training session about the Gentoo distribution on Saturday 13th, 2008. First of a series of 18, this course enabled 23 participants to familiarize themselves with the Gentoo LiveCD and to briefly learn about the command line utilities involved when installing Gentoo.

This training session was made possible thanks to the Gentoo-Quebec team as well as Copernic, which provided a training room and the network installation for all participants. For more information, please consult the Internet web site at the following address (in French): http://gentoo-quebec.org

Figure 3.1: Learning Gentoo in Quebec

Planet Gentoo

OLPC XO: Daniel Drake works for the One Laptop Per Child project which release the XO unit some time ago, which ships with a special version of Linux. But it's also possible to use standard desktop distributions.

Surfing the MIPS: Stuart Longland started the compilation some months ago, but now Firefox 3 on MIPS is there.

Gentoo book revisited: The first German book published about Gentoo has been reworked by its author Tobias Scherbaum.

RAID tips: Robin H. Johnson has a little howto about having missing slots in a RAID and then move in the real disks later.

Not dead: Steve Dibb and Ben de Groot address a few things about Gentoo.

Beautifying Xfce: Joshua Saddler has some tips and screenshots on creating a beautiful, yet practical Xfce environment using small, lightweight applications.

Gentoo in the News

Gentoo gaming servers spotted: Internode has relaunched its Games On Net service. The good-sized network runs (at least in part) on Gentoo Linux.

4.  Tips and Tricks

Running commands on many machines

If you have been logging into your horde of Gentoo boxes one by one in order to run a command or two, this tip should help you save a lot of time. We provide a glimpse into some of the methods you can use to run commands on multiple machines both sequentially and in parellel.

The first method is the most primitive. It uses pure bash. Let's say we have ten machines with the hostnames gentoo-box-1, gentoo-box-2, and so on. We want to run emerge --info on each machine at the same time. Here is what we do:

$ for i in `seq 10`; do ssh gentoo-box-$i "emerge --info"; done

If you don't have public key encryption setup for ssh, you should read the OpenSSH Key Management series of articles. You may also want to consult this guide.

If you don't want to hassle with public key encryption, writing complicated "for" loops in bash, and want to run interactive commands, there is a good option for you: Cluster SSH. Let's install it:

# emerge clusterssh

Cluster SSH requires X11 in order to work. Cluster SSH works by opening an xterm window for every machine in the list you provide. It also opens a small command window where you can type text that gets relayed to other machines' command lines at the same time. To do the same thing we did before with the ten Gentoo boxes, we do the following Cluster SSH:

$ cssh gentoo-box-{1,2,3,4,5,6,7,8,9}

First, you will see the machines ask for passwords unless you have public key encryption set up for them. If one of your machines has a different password, no worries, you can just click on the window of the machine and type it there. Once you see yourself logged into all of the machines, you can type commands to all of them at once or individually.

Another alternative is to use Tentakel. Tentakel is used in a more static way. Users modify a static configuration file, and then tell Tentakel which group of hosts it should connect to. First, we need to install Tentakel:

# emerge tentakel

Next, we create a configuration file:

# echo "set ssh_path=\"`which ssh`\"" >> /etc/tentakel.conf
# echo "set method=\"ssh\"" >> /etc/tentakel.conf
# echo 'group ten_gentoos (user="root")' >> /etc/tentakel.conf
# for i in `seq 10`; do echo -e "\t+gentoo-box-$i"; done >> /etc/tentakel.conf

It might be more practical to simply edit the sample configuration file shipped with Tentakel:

# cp /usr/share/doc/tentakel/tentakel.conf.example /etc/tentakel.conf
# nano -w /etc/tentakel.conf

Once you have everything configured, it's time to run Tentakel:

$ tentakel -g ten_gentoos

This will launch Tentakel's interactive command interface. In order to run a command use the provided exec function:

$ exec emerge --info

If you are lost in Tentakel's command interface, just run help. You can run Tentakel without the interactive command interface like this:

$ tentakel -g ten_gentoos "emerge --info"

These tips only brush the surface of the programs available to distribute commands to machines. If you're unhappy with Cluster SSH and Tentakel, you may want to try out dsh, pdsh, pconsole, and shmux.

Iotop

When a process is slowing down a computer that has plenty of extra memory and disk space, it is probably because of cpu usage or input/output (I/O). Most Gentooers are used to using top to locate those pesky CPU and memory hogs, but few have ever used iotop to find the disk usage hogs.

iotop displays columns for the I/O bandwidth read and written by each process/thread during the sampling period. It also displays the percentage of time the thread/process spent while swapping in and while waiting on I/O. In addition the total I/O bandwidth read and written during the sampling period is displayed at the top of the interface.

Install it with emerge iotop. If Portage warned you that you don't have the necessary kernel options (TASKSTATS and TASK_IO_ACCOUNTING) to run the tool, then you will need to recompile your kernel with the options shown below.

General Setup -->
  [*] Export task/process statistics through netlink
  [ ]   Enable per-task delay accounting
  [*]   Enable extended accounting over taskstats
  [*]     Enable per-task storage I/O accounting

Once you've booted into your reconfigured kernel, you can run iotop from the commandline. Here's what it might look like if you were backing up a DVD:

$ iotop
Total DISK READ: 387.25 K/s | Total DISK WRITE: 221.29 K/s
  PID USER      DISK READ  DISK WRITE   SWAPIN    IO>    COMMAND
 7703 root      387.25 K/s       0 B/s  0.00 %  0.00 % tccat -i /shared/...
  211 root           0 B/s   13.83 K/s  0.00 %  0.00 % [pdflush]
 7672 root           0 B/s  207.46 K/s  0.00 %  0.00 % transcode -H 10 ...

A misbehaving user might have the following output:

$ iotop
Total DISK READ: 5.21 K/s | Total DISK WRITE: 7.37 M/s
  PID USER      DISK READ  DISK WRITE   SWAPIN    IO>    COMMAND
 7936 user1       5.21 K/s    7.37 M/s  0.00 %  0.00 % dd if /dev/zero of ./bigfile

iotop is a good way to see what's eating your disks, so that you can reallocate resources when needed. The program has a few options available, so run iotop --help to get a summary of its capabilities.

Using lsof: revisited

Last month's edition of Tips and Tricks showed you how to use lsof to find open files and directories.

An astute reader emailed the GMN to show another use of lsof: to check for processes that should be restarted after package updates.

For example, after upgrading a package like openssl, you might need to restart a mail server, a web server, or even several client applications. lsof is kind enough to point out the open files that have been deleted, so you can easily spot these processes:

# lsof | grep 'DEL.*lib' | cut -f 1 -d ' ' | sort -u

Restarting processes after an upgrade is especially important when the library includes a security fix.

5.  Gentoo developer moves

Summary

Gentoo is made up of 242 active developers, of which 43 are currently away. Gentoo has recruited a total of 649 developers since its inception.

Moves

The following developers recently left the Gentoo project:

• None this month

Adds

The following developers recently joined the Gentoo project:

• Gordon Malm joined the Hardened team
• Matthew Summers joined the Trustees as secretary
• Ron Gemeinhardt joined the Forums team

Changes

The following developers recently changed roles within the Gentoo project:

• Jorge Manuel B. S. Vicetto joined the undertakers team, and will maintain various ebuilds
• Deedra M. Waters joined the Trustees

6.  Portage

Summary

This section summarizes the current state of the Portage tree. Unfortunately, we will not be able to publish statistics this month, as we update our tools to work with the newly introduced EAPI-2. We should be able to resume next issue though, stay tuned!

The following section lists packages that have either been moved or added to the tree. The package removals come from many locations, including the Treecleaners and various developers.

Removals:

Additions:

7.  Bugzilla

Statistics

The Gentoo community uses Bugzilla (bugs.gentoo.org) to record and track bugs, notifications, suggestions and other interactions with the development team. The following chart summarizes activity on Bugzilla between 30 August 2008 and 29 September 2008.

Figure 7.1: Bug activity split-up

Of the 12369 currently open bugs: 12 are labeled blocker, 106 are labeled critical, and 451 are labeled major.

Closed bug ranking

The developers and teams who have closed the most bugs during this period are as follows.

Figure 7.2: Bug closed rankings

Assigned bug ranking

The developers and teams who have been assigned the most bugs during this period are as follows.

Figure 7.3: Bugs assigned rankings

8.  Getting Involved

The GMN relies on volunteers and members of the community for content every month. If you are interested in writing for the GMN, do write in to gmn-writers@gentoo.org with your articles in plaintext or GuideXML format.

We solicit feedback from all our readers on the newsletter. If you have any ideas for articles, sections, or have anything to say about the GMN, don't hesitate to email us at gmn-feedback@gentoo.org.

You can also give us your feedback and comment on this particular issue of the GMN on the forum thread.

9.  GMN subscription information

To subscribe to the Gentoo Monthly Newsletter, send a blank e-mail to gentoo-gmn+subscribe@gentoo.org.

To unsubscribe to the Gentoo Monthly Newsletter, send a blank e-mail to gentoo-gmn+unsubscribe@gentoo.org from the e-mail address you are subscribed under.

10.  Other languages

The Gentoo Monthly Newsletter is available in the following languages:

• English
• German
• Italian
• Japanese
• Polish
• Spanish
• Simplified Chinese