Dax's Blog

Having owned several IBM T-series ThinkPads I've always been a fan. The ownership of T-series has spread throughout the troupe of Linux Training instructors here at Guru Labs as lesser laptops have fallen to the wayside.

I've had my current T42p for almost three years now. I've been very happy with it. The build quality is excellent, and it anyone looking at it would never guess it has been used daily for the last three years. The Linux support is superb. The only problem is that the 2.0 Ghz Pentium-m CPU in it doesn't support PAE so Xen in RHEL5/FC6 doesn't work.

Today I found that IBM has posted details on the new Santa Rosa chipset based T61 laptops to be released next month. I plan on picking one up to replace my T42p. Some of the highlights:

* All the benefits of Santa Rosa platform
* LCD roll cage
* Firewire port
* NVIDIA Quadro 140M replaces ATI as high video card option
* Four-in-one media reader
* New Intel 4965AGN WiFi card

More information is available in the Announcement Letter (HTML) or Announcement Letter (PDF)

There has been lots of activity the past little while on the software development front. Here is a sampling of few things that caught my eye.

SUSE Enterprise Linux 10

On Monday, Novell released the long awaited SUSE Linux Enterprise Server and Desktop version 10. Guru Lab's Linux courseware and classes cover both SUSE Linux Enterprise as well as Red Hat Linux Enterprise and we are working on releasing updated materials to cover this new version 10 release (and later this year, RHEL5).

Major Squid Release

The Squid web proxy server has a new major v2.6 release after several years. Some of the new features include better scalability, a "totally transparent" mode which rewrites layer 3 and 4 address and port numbers, support for Negotiate/Kerberos authentication, hardware assisted SSL support, and many other features. I authored the Squid chapter and lab used in our GL275: Enterprise Linux Services class and I'm excited about adding coverage the new v2.6 features. Too bad that none of the 2006 Enterprise Linux releases will include Squid v2.6.

Compiz in Fedora

On the Fedora Core v6 and Red Hat Enterprise Linux v5 development front there has been a few things of note. The OpenGL window and compositing manger, Compiz has been added to rawhide. It seems that 2006 is the year of ubber eye-candy in Linux. I doubt it will ship as part of RHEL5, but FC6 desktops should be all set. On difference between SUSE and Fedora is that Compiz sits on top of AIGLX instead of XGL. A Red Hat developer provides some more details in a post to the fedora-devel-list.

Essential Perl Modules now in Fedora

Several years ago when we added comprehensive LDAP coverage to the GL275 class we ran into a deficiency. We teach the best practice approaches to using LDAP as a NIS replacement. That often involves importing user accounts into LDAP from files in /etc. The PADL migration tools leave a lot to be desired from a functionality and user friendliness perspective. So I wrote a new migration tool in perl called "ldapmigrate". Of course when communicating with the LDAP server it is best to do so over an encrypted SSL/TLS connection. To that end my "ldapmigrate" script makes use of the perl modules IO-Socket-SSL and Net_SSLeay. By having those two modules installed the perl LDAP module can make the encrypted connections. Although SUSE included those modules as part of the distribution, Red Hat did not and I filed a bug report in 2003 to add them. In the interim we compiled and provided those modules in class. Finally, today they were added to rawhide so those modules will part of Fedora Core v6 and RHEL5.

I've had my shiny new Treo700p for the past week and I thought I share a few things I've noticed about upgrading from my Treo650.

By far, the best new feature is support for super fast (slightly less fast than DSL) data access via EVDO. The speed difference is incredible and the latency is about 1/2 of what it used to be.

Benefits of the speed increase (and latency decrease):

• SSH sessions have nearly no lag! (note that I use pssh as my PalmOS SSH client)


• IRC, VNC and RDP remote desktop sessions are also greatly improved with nearly zero lag.


• Web browsing is MUCH faster due to the lower latency, faster download speeds and improvements to cache handling in Blazer v4.5.


• Doing a new email check my IMAP inbox (with 24,000+ messages) now takes about 10 seconds versus a minute on the Treo650. New emails download very fast.


• High quality streaming audio and video is now possible. I know lots of people are going gagga over the fact that Orb works. The 3GP test page worked fine for me.


• Tethering your Laptop via Bluetooth DUN results in speeds around 250Kbs. If you tether your laptop via USB the speeds are around 950Kbs!

Besides the killer speed increase there has also been a large round of polishing. Some things I've noticed in that regard include:

• The "screen is locked" dialog now shows the time.


• Contacts can be assigned a custom ring tone in the Contacts app.


• The SMS app has seen a face lift.


• The excellent Documents To Go app with PDF, MS Word, MS Excel (incidentally, it does calculations on TEXT cells the same way as Excel), MS Powerpoint support is now included and installed the ROM.

All in all I'm very pleased with the upgrade to the Treo700p.

Uggh. I hate to do this, but I don't want to have someone trip over this unmarked landmind and possibly lose a bunch of money/reputation/sanity.

All over the world OpenOffice.org/StarOffice is pitched as a replacement for Microsoft office including Excel.

As such OO calc can read MS Excel files, but it does something very very bad. It performs calculations DIFFERENTLY than Excel (no warnings even).

This is pure evil.

The issue is that Excel will perform math calculations on numbers even if the cell is formatted as "TEXT" or has text in it. The very newest Excel indicates something is amiss by having a small green triangle in the corner of the cell, but this behavior is not likely to ever change so as to maintain backwards compatibility.

The problem with OpenOffice Calc is that in most situations (but not always) it will silently ignore numbers in "text" cells that are part of formulas or calculations and in the end produce wrong answers.

This Excel compatibility problem was reported 5 years ago!

See http://www.openoffice.org/issues/show_bug.cgi?id=5658 for the sad sad commentary, many duplicate bug reports as well as the unfortunate inability by the OO.org developer(s) to consider this a problem of any importance.

For example, some developer comments:

"not a defect."
"Not a bug ! Text is text and not a number so you can't calculate with text."
"IMHO not a bug from Calc but from Excel"
"we are not an Excel clone and will not be !"

I *almost* had a $20,000 mistake (not in my favor) thanks to OpenOffice.org Calc while I was creating an invoice from an Excel XLS file emailed to me by a client.

Server vendors like Dell love Linux as it helps them sell hardware. It is in their best interest to have their servers work well with Linux.

Dell has long had a server management software called Dell OpenManage Server Administrator (OMSA) which provides a command line and web interface to monitors hardware details and failures as well as has the ability to "plug-in" to various datacenter management platforms like HP OpenView, CA Unicenter, and Novell Zenworks.

Historically OMSA required several binary-only kernel modules for drivers to the system management chips. This meant that if you used OMSA, it would "taint" your kernel rendering your system unsupported by kernel developers (although you could still get support from your Enterprise Linux vendor and Dell).

Today I noticed that Dell OpenManage Server Administrator v5.0 was released. The press release didn't mention this, but digging deeper I discovered this tidbit:

Starting with OMSA 5.0, all necessary kernel components are now fully open source, GPL licensed, and included in kernel.org 2.6.x. This includes the OpenIPMI drivers/char/ipmi/ipmi* drivers, drivers/firmware/dell_rbu Remote BIOS Update driver, and drivers/firmware/dcdbas Dell Base Systems Managment driver. This should make it much easier to install and run OMSA on a variety of Linux distributions (userspace library incompatibilities, if any, notwithstanding).

That is very cool! Well done Dell.

I also found out today that Dell makes it easy (relatively so) to install OMSA via a "unofficial" yum repository. Do any other big hardware vendors have yum repos for their management tools?

Information on the repository is available at: http://linux.dell.com/repo/software/

Us folks at Guru Labs have long been Treo users and most everyone at the office has one.

There are extremely powerful communication tool and whenever we doing a Linux training gig on the road the Treo makes it easy to stay in touch (and even drop in on #utah).

The Treo700p will be official announced on Monday May 15th 2006. However, in some places of the world that time has already arrived and the press embargo has been lifted.

For official/non-rumor Treo700p details check out the first article to be published at Treo Central, titled "Palm Reveals Treo 700p Smartphone".

The 2nd article now online is from Palm themselves, see the "Treo 700p Smartphone". There is a PDF as well as a flash demo.

An anonymous Sprint employee posted page "4" of their weekly sales "playbook". It in it shows the Treo 700 launching on May 28th. In the thread discussing this new info it has also confirmed that this is the Treo 700p (and not the 700w).

This info is from www.TreoCentral.com which has the best forums for Treo owners and fans.

The Treo700p is soon to be released and I plan on upgrading. Some of the new (rumored) features to be included are:

* EV-DO support on CDMA networks
** Can receive incoming calls while actively using data
* Increase of built-in memory to 64MB
* Update of all built-in apps
** New "fast mode" in blazer
* 1.3MP camera
* FAT32 support (can be hacked into a Treo650 today with a custom rom)
* Enhanced keyboard

The EV-DO support is probably the "killer app" as it provides DSL-like speeds.

The N. Utah Sprint EV-DO coverage map shows EV-DO coverage available today in orange and future coverage in beige.

I look forward to the EV-DO Rev A rollouts as that greatly increases the speed down and up while providing much better latency that will make VoIP and interactive apps (such as ssh) a joy to use. Unfortunately I doubt the EV-DO radio in the Treo700p will support EV-DO Rev A. Oh well, it just gives me yet another reason to upgrade to a future Linux based Treo.

Palm has just announced a Trade-In Program for old PDAs and SmartPhones that can be used as credit towards the purchase of a new Treo 700p (or any Palm PDA).

Some of the Trade-In values I checked:

Treo 650 in excellent condition = $170
Treo 650 in good condition = $142
Treo 600 in excellent condition = $65
Treo 600 in good condition = $53

The market for Linux training is heating up and we are looking for more talented folks to become Guru instructors. We recently filled a position (big wave to Clint), but we have several more spots open.

We have traditionally hired via word-of-mouth.

Job details follow...

=======================
Job title: Guru
Location: Bountiful, Utah and North America (see description below)
Type: full-time position with benefits
Salary: Negotiable depending on experience
Description: You would be joining an extremely talented team of Linux
enthusiasts. Core job responsibilities include teaching Linux classes
locally and abroad, and developing and updating Linux course materials.
Requirements: Strong Linux administration skills with additional broad topic knowledge in security, networking, scripting, and programming very beneficial. The ability
to communicate effectively is required with an outgoing personality a plus. The willingness and
ability to travel also required.

Pros:
* No dealing with pointy haired bosses, corporate red-tape, hostile
workplace politics, etc.
* We are a small company that has been in business for 7 profitable
years. Owned 100% by employees with no outside funding allows us
to operate without external pressures.
* Guru Labs environment and culture foster rapid skills development.
You will be constantly working with smart people on cutting edge Linux
projects. Teaching Linux will add a whole new depth to what you thought
you already knew.
* Gurus are actively encouraged to participate in the open source community.
* Fun travel at least 2 weeks a month. We teach Linux classes (both
public enrollment, and private corporate on-site) all over the US and
beyond. Spend your evenings enjoying local attractions and culinary
wonders.

Cons:
* Expensed meals from the best restaurants in the country will soon
make all the restaurants in Utah seem a bit dull.
* Being surrounded by geeks with tech gadgets may give you "gadget
envy" and lead to increased electronics purchases.
* Your ego may take a hit as you discover that having your laptop
multi-boot between 5 Linux distros sporting custom kernels that you
built and packaged is suddenly the norm. :)

Send resumes to jobs@gurulabs.com

When installing and/or upgrading packages using the /usr/bin/rpm command you have several choices depending on the exact outcome desired and the pre-existing situation.

First one should be aware of one of the RPM rules that is the main factor in this choice, namely "A file can only be 'owned' by a single RPM package". As with all rules in the UNIX/Linux it is possible to override this rule, but you get to keep all the pieces when stuff breaks.

Because of this rule, for the vast majority of packages you might install, you can only have one version installed.

For example, lets say you have two RPMs for the Apache web server.

httpd-2.0.54-10.3
httpd-2.2.0-5.1.2

(the package names come from Fedora Core v4 and v5 respectively).

You can examining the packages (before installation) and see what files are contained. In this case we'll just look at what files have "sbin" in their path since the complete list is over 300 files.

First the package for Apache version 2.0:

$ rpm -qlp httpd-2.0.54-10.3*rpm | grep sbin
/usr/sbin/apachectl
/usr/sbin/httpd
/usr/sbin/httpd.worker
/usr/sbin/rotatelogs
/usr/sbin/suexec

And for Apache version 2.2:

$ rpm -ql httpd-2.2.0-5.1.2 | grep sbin
/usr/sbin/apachectl
/usr/sbin/htcacheclean
/usr/sbin/httpd
/usr/sbin/httpd.worker
/usr/sbin/httxt2dbm
/usr/sbin/rotatelogs
/usr/sbin/suexec

Out of the 300+ files if a single file is the same you can't have both packages installed at the same time. Really the constraint isn't the two Apache RPMs, but the entire set of RPMs that are installed or will be installed on a box. No files can "conflict" (be the same).

With this rule covered, now what RPM options are available and when would one use them. Pretty much you will always use the "vh" options to get verbose output and hash (#) marks. But of the primary action options are "-i", "-U", and "-F".

* "-i". Performs an installation without removing (aka upgrading) any older version of the package. If you have an older version of the package installed, most likely THE COMMAND WILL FAIL because of overlapping files (see the Apache example above). So, for the most part, you can only use "-i" if you know ahead of time that you don't have an older version of the package already installed.

This begs the question, "When can I have two versions of a package installed simultaneously?". There are two situations, one fairly common and the other not so common.

* With the "kernel" RPM package. It turns out that every file provided by the kernel RPM package has the kernel version string somewhere in the full path, for example:

/lib/modules/2.6.15-1.2054_FC5/kernel/arch/i386/crypto/aes-i586.ko

Because of that you CAN have multiple kernel RPM packages installed at the same time, and you might actually WANT to. You might want to because the kernel is very critical to the operation of the system and if you install a new kernel version, and for whatever reason (bad driver, bug, etc) it doesn't work properly or won't boot, by having your old "known good" kernel installed you can easily recover (reboot and select the old kernel from the GRUB menu).

* The other case is when trying to run an old binary you discover it is requires /usr/lib/libfoo.so.1 and you have /usr/lib/libfoo.so.2 installed. Like the kernel RPM, most (but not all), library packages have the version string embedded in the file name and therefore don't conflict.

By using "-i" you can install libfoo-1.0.18.i386.rpm alongside libfoo-2.0.22.i386.rpm.

Finally, for the sake of completeness another related question "How can I have two packages installed where both are supplying a file with same full path?". Here are some example scenarios:

* sendmail and postfix both trying to provide /usr/sbin/sendmail
* SUN Java, IBM Java, and GCJ trying to provide /usr/bin/java
* CUPS, LPRng both trying to provide /usr/bin/lpr

The answer is (as is often the case in computer science), don't have the files conflict and use an abstraction layer. This was first done by the Debian folks in the creation of the "alternatives" system, it is used very widely in Debian/Ubuntu for lots of different packages. Red Hat adopted it during the 7.x time frame but used it just with MTAs (sendmail, postfix) and printing subsystems. SUSE has now adopted it with version 10.0 but only for Java packages from the jpackage project. The complete discussion of the alternatives system is beyond the scope of this blog post. We do have excellent coverage in our Linux training classes though.

* "-F". Performs an installation and removes (aka upgrades) any older version of the package if and only if you DO have an older version of the package installed. This option I like to call the "upgrade only" option. It is relic of the olden days of updating a Linux box with errata. Back then you update your system with the updates by:

1. Download all available updates (using ftp and mget *rpm) into a local directory.
2. In that directory run "rpm -Fvh *rpm".

This way you wouldn't install any new software packages that happened to have an update and instead you would just update the packages you did have installed.

Today we keep our systems current with smarter methods such as "yum -y update, you, up2date, rug, etc".

* "-U". This option performs an install if you don't have an older version already installed, and an upgrade if you do. I call it the "install or update as needed" option.

So to answer the question, "What RPM option does Dax Kelson use to install or upgrade RPM packages?" the answer is, "I try not to use /usr/bin/rpm unless I'm installing packages I've created myself or manually downloaded." Instead to install software I use a front end that figures out and downloads the dependencies automatically for me. For example:

* yum install packagename ...
* yast -i packagename ...
* up2date packagename ...

In the case when I've created my own RPM or done a manual download of a RPM package I like to use the "-U" option. This way RPM does the right thing (install or upgrade as needed) for me and I don't have to keep track of mentally if I already have the package installed.