CentOS Pulse #1002 - 1 April 2010

1. Foreword

Welcome to another release of the Newsletter. In this issue we talk about the ongoing build of CentOS 5.5 and we have another interview with someone from the community. Furthermore, we bring you updates concerning this amazing Operating System.

Have fun reading,

The NewsletterGroup

2. Announcements

Several official announcements were made the past 4 weeks and here we reiterate them.

• There is some news from the testing front. The idea is to put in place an automated testing system with all the bells and whistles. You can now contribute by submitting kickstart files and test scripts. More Info

• Red Hat Enterprise Linux 5.5 has been released.

• Registration is now open for the 2010 Red Hat Summit http://www.redhat.com/about/news/prarchive/2010/summit-registration.html

Please remember that CentOS is in no way officially connected to Red Hat. I am just posting these announcements because they might interest CentOS users.

3. Interview

This month we have an interview with Timo Schoeler, who is a Systems Administrator at Inter.Net Germany GmbH, based in Berlin. We are always on the look out for interesting people to interview, so if you would like to contribute, please just speak up on the centos-docs mailing list.

I have now received quite a few interviews. Sorry that we can not publish all of them straight away so, if you have contributed one, please be patient.

3.1. How many instances of CentOS do you roughly run? (Kernels, so Xen instances count as one)

If you don't mind, I'll talk about both the setup running at the company where I'm employed -- which is Inter.Net Germany GmbH, based in Berlin -- as well as my own private setup.

My private setup consists of three machines in our data centre, which run CentOS 5.4 as Dom0 as well as a bunch of DomUs upon each (all CentOS). In front of them there's a load balancer based on OpenBSD.

For the company setup, there is well into the three-digit numbers of CentOS instances running here. However we have a very mixed setup of FreeBSD (which is the OS on most machines here), CentOS, as well as a bunch of 'the other usual suspects'.

This is without the installations that our root server customers may have done. We also sell root servers http://hosting.de.inter.net/rootserver/ upon which CentOS can be installed, amongst some other distros and FreeBSD. One can install CentOS in several ways: 'automatic', which is a kickstart-based variant, or 'manual', where the user has VNC access to the machine and runs the well-known installer. This gives the user more possibilities regarding disk partitioning, setting up md-based RAIDs, etc.

3.2. What do you like the most about CentOS?

Honestly, CentOS was the first Linux distribution that I was not disappointed with after about a week or so. My very first experiences with Unix were on the BSD side of life (NetBSD, to be specific), with excursions now and then to commercial Unices (like IRIX, AIX, Solaris, HP-UX) and GNU/Linux. Linux was a bit too chaotic for me, as I was totally spoilt by the BSD documentation but CentOS really changed my point of view here. Of course, the more 'exotic' tasks are (think of an active-active load balancing), the more chaotic documentation gets, as it is usually spread throughout mailing lists, fora, blogs and comments in CVS or git repos.

3.3. What really drives you up the wall?

Lame documentation! That was the most annoying thing when I did my first excursions into the Linux side of life. As BSD user you're totally spoilt. Everything is documented in almost a perfect way. Linux is different here but I think going to catch up. At least, I hope so and I'm willing to contribute in that area. My experience is that you'll remember the day good documentation saved (or ruined) your life.

3.4. How do you manage packages/installs maintenance?

Spacewalk. I also follow http://twitter.com/CentOS_Announce so I see updates immediately and then can decide whether I really have to act ASAP or delay certain updates until the next maintainance window.

3.5. What software do you use? (NFS, Xen, ldap, apache, etc...)

Run by or on CentOS (again, this is talking about both company as well as private use) there's a wide range of software, applications and services. I'd mention Xen and KVM, as well as OpenVZ first. At the moment, there are much more Xen-based machines than KVM, which is likely to change in future due to Red Hat's commitment towards KVM and all the bustle taking place in Xen-space (just watch the kernel mailing lists).

We have CentOS based machines that run routing daemons (quagga et al.), as well as databases (Oracle, MySQL, PostgreSQL), web servers, mail servers or communication in general, which includes VoIP, Fax, and Jabber, for example, network management (nagios, cacti) . . . all sort of things.

A setup that I'm very proud of is http://www.zerowasteplanet.com which is a portal that a good friend of mine builds. It's about reducing waste to a minimum and motivate people to recycle. Enabling them to do so by providing decent information as to what is available, in which quantities, which composition, etc. The portal runs in a DomU and uses lighttpd, PHP and a PostgreSQL backend, among other glue.

This is the server stuff. My office workstation as well as my machine at home also run CentOS, accompanied by the usual office stuff like OpenOffice, The Gimp, VLC, XMMS and so on. I'd like to mention NetBSD's pkgsrc http://www.netbsd.org/docs/software/packages.html which is a great source of software that can't be found in any repo. It's better as building software from source, because it does handle its installed packages, similar to yum. However it fetches the sources, patches them if needed, builds and installs them (usually in a dedicated directory, so that it doesn't have to mess with Base or additional repo's stuff).

3.6. What is really special about your installation?

We seem to have some sort of 'affinity' to 'living on the bleeding edge'. In a project not too long ago we discovered quite a few bugs. They were not CentOS specific, however two of them were real show stoppers. Sometimes a hint from mailing lists does help to create a patch for the problem, sometimes one has to wade through the source code. However, although hitting bugs is annoying sometimes, for me it's part of the 'fun side' of the job because there's so many things to learn.

3.7. What is the biggest problem you have ever encountered while running CentOS?

Oh. Now I have to think about it some time . . . The servers I touch(ed) really run without problems. My home 'workstation' had some issues, though. (Sidenote: I don't like using the term 'workstation' for x86-based machines. I like to remember the golden 80s/90s, when 'workstations' wore labels like 'SGI', 'IBM', 'Sun', or 'HP' and were shiny and expensive.) It's an AMD Phenom II with 8GiByte RAM, on-board gfx and two RAID sets to store my data (small home server). Pretty straight-forward configuration but the on-board NIC is some sort of crappy 'Atmel' device. Trying to get the machine stable with the driver they provide was plain impossible, regardless of the tricks I tried (even removing all the memory except 2GiBytes, because there were stability problems with that driver in machines with much memory). So, I plugged in an Intel NIC, disabled the on-board NIC in the BIOS and . . . voila, the machine runs just as a CentOS machine should: absolutely rock solid.

3.8. What would you like to see in the future?

Keep on doing the great work! That is my major wish for the future. Overall I'm very happy with CentOS itself and the community. However, I'd like to see more activity in the non-x86 corner, especially the PowerPC port is something I'd like to see (again). I was totally into hacking on NetBSD/PowerPC half a decade ago and I still love Power & PowerPC gear. I have some IBM Power4+ and Power5 machines I'd like to see booting CentOS. Even more after Red Hat said that there will be RHEL6 for Power . . .

3.9. What is the the next big thing you are going to approach while using CentOS (using ksplice, for example)

Speaking for my personal goals, I'd like to finally finish my mail server migration from FreeBSD to CentOS. It's not that I'm not happy running this service on FreeBSD, it's just because it runs on very old, yet rock solid hardware and the only service that is running on this machine (an IBM Xseries 330 in maxed-out configuration). It's a Postfix/Mailman/Cyrus setup with all the anti-spam yaddayadda. A total waste of resources. All other services (like Web server, FTP/SFTP, Jabber, etc) already moved to a Xen domU on one of my bigger irons (also IBM Xseries). It's the 'next big thing' for me as it already took 3 years due to total lack of motivation^Wtime.

The next really big thing would be a setup to (successfully!) test some cluster file system that performs well in any scenario. Most of the cluster file systems available today either cost lots of money or have some kind of problem that is finally a show stopper. I recently read about Ceph http://ceph.newdream.net/ becoming part of Linux 2.6.34. The papers covering Ceph are promising and I'd like to test it. Maybe there's a backport of it or CentOS 6 will feature it? Until then, I guess Fedora will pave way.

3.10. And I need some funny fact about you.

Pig-tailed, horseman, eMail addict (I have all my mails back to 1995). I somehow 'collect' computers which are almost exclusively non PC machines like SGI, IBM RS/6000, Sun, Amigas and more exotic machines, although I try not to. I have already sold some but I just cannot sell my Power Indigo2 with its exotic R8000 CPU, for example . . . However, for some machines, I really hope that they will be of use sooner or later, especially the not too old Power gear (Power 275, Power 285), for building CentOS 5.5 for Power. Ah, and I have one of my NeXT slabs http://www.channelu.com/NeXT/Black/ setup running NetBSD headless, which requires a pretty screwball hardware hack http://netbsd.org/ports/next68k/faq.html#no-monitor.

4. Featured Articles

Yesterday another update release of RHEL5 was born.

These (minor) update releases typically provide feature enhancements, bugfixes and new hardware support. And, as such, come as a set of new installation media (CDs and DVD). Some of you may have already looked at the Beta release and, apart from stabilizing the product, a lot of what is known from that Beta is true for the real RHEL 5.5 release.

From the release notes: Highlights of the Red Hat Enterprise Linux 5.5 release include hardware enablement for the Intel Boxboro-EX platform, AMD Magny-Cours processor and IBM Power7 processor. Virtualization is improved, with support for multiple 10 GigE SR-IOV cards and automatic usage of hugepages for virtual guest memory when enabled on the system. Interoperability improvements include updates to OpenOffice for Microsoft Office 2007 filters, Samba for Windows 7 compatibility and boot support for virtual machines using Microsoft based PXE services.

But our own summary of technical details would highlight:

• Kickstart improvements to logging post-install
• New hardware driver support (pmcraid, ibmvfs, bfa, be2iscsi)
• Updated hardware support (too many to list but includes wireless driver rebase)
• Support for Intel's Boxboro-EX and Boxboro-MC, AMD's Magny-Cours and IBM's Power7 processor
• Run-time memory allocation for KVM guests (memory ballooning)
• PCI passthrough improvements (hotswapping PCI devices, 1:1 performance improvements)
• Detecting kernel tasks stuck in the uninterruptible sleep state (D-state)
• Improved CFQ I/O scheduler performance
• Kernel CIFS updates and new GFS mount option (for troubleshooting)
• GDB, Valgrind and Systemtap updates for improved debugging
• Software updates (openoffice, metacity, samba, freeradius)

Apart from this, Red Hat also shares Technology Previews within each release. Functionality that is not yet supported but available for testing purposes includes:

• FCoE (Fibre Channel over Ethernet)
• ext4 filesystem support
• gcc 4.4 and new glibc malloc
• Trusted Platform Module (TPM) hardware support
• eCryptfs cryptographic filesystem
• FreeIPMI
• Stateless Linux
• SGPIO Support for dmraid
• Device Failure Monitoring of RAID sets
• iSER support (block storage transfer across a network)

Which means that the above Technology Preview features of RHEL5.5 may become part of a future RHEL5 release!

Even though there is no predicted timeline for CentOS releases, please keep in mind that a lot of work is involved in crafting a release and it takes a lot of personal effort, too. Even if many people are anxious to see the new version, packages do not build faster if a lot of people ask about the status on the Mailing List.

With this release, the question about CentOS 6 also arises. With the expected release of RHEL6 at the end of 2010, this gives you a lot of time to play with CentOS 5.5.

The original article was published by Field Commander Wieers on his blog and has been modified by the Newsletter team.

5. Tip Of The Newsletter

If you have a good tip or know of a really good program that you would like to share, please send us an email.

5.1. Where's the Documentation?

To quickly list documentation relating to a package, you can use either of the following two options:

rpm -qd <packagename>

• This will show you the documentation contained in that rpm or, if you only have a filename, you can do:

rpm -qdf /path/to/file

• and rpm will show you the documentation in the package from which that file is originates.

5.2. Remove all those 32bit packages

The base install of CentOS on a 64-bit machine often installs a lot of 32-bit packages that are not really needed. So removing them can make sense. But please be careful as there are packages that do rely on the 32-bit versions. So only more advanced users should really try doing this:

rpm -qa --qf '%{name}.%{arch}\n' | grep 'i[3456]86$' | xargs rpm -e

yum remove glibc.i686

which will take care of the removal of all the *.i?86 rpm packages.

When one removes the 32-bit packages, the common/overlap parts of the dual arch installed rpms (ie man pages, doc, config files) will also be removed, so caveat.

6. Jokes and Funny Stuff

6.1. The RH edition of the Newsletter

6.2. Ping

<erno> Hmm. I've lost a machine. Literally _lost_. It responds to ping, it works completely, I just can't figure out where in my apartment it is. source

6.3. Really

"When you say 'I wrote a program that crashed Windows', people just stare at you blankly and say 'Hey, I got those with the system, *for free*'." -- Linus Torvalds source

7. CentOS in the Spotlight

The following articles mention CentOS and are a good resource to understand how the media (and public) view CentOS.

• http://www.journaldugeek.com/2010/03/17/quand-un-projectionniste-reboot-son-matos-avant-une-seance-de-cinema/

8. User Desktops

The following picture is of the desktop of a CentOS user. Please send us your picture(s), if you would like to have yours featured. Of course all machines have to run CentOS to be accepted. Please blur any private content.

9. iPad release on 1st April

We are proud to announce the release of CentOS on the iPad. Porting began as soon as we managed to get one of the pre-release pads and we are happy to say that we managed to finish the port in time for the official Apple release. So now YOU can choose what you want to do with your iPad.

10. CentOS Errata

This section highlights the most severe security updates for each supported CentOS release, whilst providing a summary and short links to the reference of the security issue.

10.1. CentOS-3

No critical updates were released in March 2010.

10.2. CentOS-4

No critical updates were released in March 2010.

10.3. CentOS-5

No critical updates were released in March 2010.

11. Upcoming Events

The CentOS Promo SIG organizes CentOS presence (booths, presentations, etc) at various conferences and trade shows. Here we highlight upcoming events. If you are interested in helping, please join the Promo SIG.

• 2010-04-10 -> 2010-04-11: Linux Open Administration Days 2010, Antwerp, Belgium -- official site

• 2010-06-09 -> 2010-06-12: LinuxTag 2010, Berlin, Germany -- official site

• 2010-08-10 -> 2010-08-12: LinuxCon 2010, Boston, US -- official site

• 2010-08-21 -> 2010-08-22: FrOSCon 2010, St. Augustin, Germany -- official site

• 2010-09-17 -> 2010-09-18: FrOSCamp 2010, Zurich, Switzerland -- official site

• 2010-11-06 -> 2010-11-07: T-DOSE 2010, Eindhoven, the Netherlands -- official site

Like previous years, CentOS was at the Chemnitz Linux Days. We hope everyone had a good time there.

12. Contributing to this newsletter

We are always on the look-out for people who are interested to help:

• report on CentOS community activity
• maintain a section in the newsletter
• write an article (or hint) on an interesting topic or person

If you would like to appear in the newsletter, you will have to have contributed positively to the CentOS community and then, hopefully, get noticed by one of our reporters.

We have a special page with more information about contributing!