Oracle: Unbreak my Linux Heart

Just read a neat trick you can perform with Dell's OMSA software ... You can put the load average of your PowerEdge 2950 into the LCD screen of the server. That way it'll show how busy it is at a glance. First you'll need to figure out how many characters the LCD screen is wide. But let's say it can hold 20 characters, maximum. Then you convert the load average to a single digit using mod 20. Add the remainder of characters into the LCD. Say you have a remainder of 7: omconfig chassis frontpanel config=custom lcdindex=1 text="=======" Cool! BTW, this wasn't mine, I got it from the PowerEdge mailing list! Recommended!

Ran across an interesting tidbit on the Dell PowerEdge mailing list again. There was a question regarding the web server used in Dell's OpenManage . It turns out to be a formerly commercial web server written in Java that has since gone open source: Servertec .

While working with Subversion for our code, tools, scripts and so on, some people also wanted to put documentation inside SVN. That way, we can release code and documentation in one go. Easy, clear, practical! Or is it? It seems Subversion is not really good at handling large(r) binary files, such as executables, Word or even image files. While on paper it should be capable of doing just that, in practice you often get severe performance penalties when checking in and out binary files.

Today at work, a discussion was started relation to version control of code, tools, script and other files using IBM Rational ClearCase. I've just recently spent a lot of time digging my teeth into Subversion, so I was not amused. But corporate policy is policy, so what can you do? Well, it turns out: a lot . You may keep SVN, develop there and push releases into ClearCase. best of both worlds. CollabNet has a clearcase2svn connector . There is also a comparison of ClearCase vs. Subversion (PDF). And lot of discussions of people migrating back to SVN from ClearCase. LOL

What is lofs? LOFS, or loopback virtual file system , is a Sun Solaris local file system that can be used to provide resources within a physical system from a global zone to one or more local zones. A Zone is Sun's approximation of a virtual machine (VM), sort of.

Cyberciti writes: "Linux desktop user generally uses small hard disk and partition, but on server you need a large partition. For example, you cannot create 4TB partition size (RAID based) using fdisk command. It will not allow you to create a partition that is greater than 2TB. To solve this problem use GNU parted command with GPT. It supports Intel EFI/GPT partition tables. [...] By default Red Hat Enterprise Linux/CentOS comes with GPT kernel support. However, if you are using Debian or Ubuntu Linux, you need to recompile the kernel." Update: Check a good post on IDoLinux about using GPT or LVM to partition file systems, and if you use hardware RAID in your system, do read about optimizing the Linux file system to maximize performance.

How do you tell which memory DIMM is in which slot without shutting down your (Linux) server nor opening the case? You maybe able to use dmidecode, haven't tried that yet. But you can also use a great little tool by Dag Wieers called lshw ... Gotta love open source... :) It's available here .

The mailing list noted yesterday that Dell OMSA 5.5 is being tested. "We now have OMSA 5.5 available for testing in the Dell hardware repository. As of OMSA 5.5, yum is now an official distribution method. Due to this, 5.5 will soon move to the 'latest' repo. Please report back any failures or successes. To test the new repository, you can now go directly to http://linux.dell.com/repo/hardware/OMSA_5.5/ , and follow the instructions. With the new repository tools, you will be able to stay on a specific version of the repository, or stay up to date with the latest packages, by going to the appropriate folder (e.g. 'OMSA_5.5' or 'latest') and bootstrapping the repository."

Besides good ol' CVS and the de facto successor Subversion (SVN), the new invention and wide-spread use of distributed version control systems (DVCS) such as Mercurial, Bazaar and git (used for the Linux kernel itself) also have their advantages. For one, iBanjo says you can " suck down the entire history of a Subversion repository into a local, private repository, do all of your commits locally, make branches, experiment all you want, then “push” back up to Subversion again. For those interested in this functionality, there is now a very promising Mercurial to Subversion bridge called hgsubversion . Although still early, the bridge was done right and from the ground up using Subversion's own API and by someone with a good understanding of both svn and hg. The HOWTO is on iBanjo .

That same article on ZDNet.com also mentions that Oracle has begun to think about who it will structure its licensing schema for Cloud Computing (PDF). Other vendors will probably follow soon.

ZDNet.com : "Amazon said on Monday that it will be adding various Oracle enterprise offerings to its cloud computing service, dubbed Elastic Compute Cloud (EC2) . The move will give Amazon’s cloud services some serious enterprise heft. In a blog post, Amazon said it will offer EC2 services preloaded with Oracle’s software–Enterprise Linux (OEL), Database 11g, Fusion Middleware, Enterprise Manager and developer tools–as well as support options. For Oracle Enterprise Linux on EC2 there is a combo of the software giant’s Unbreakable Support and Amazon’s Premium Support."

Found easy instructions on How to Mirror a Subversion Repository . I'm currently using svnadmin dump to regularly dump the repositories, but eventually I'd like to hotcopy everything over to a mirror that is in stand-by mode. The latter also copies hooks and configs, so that's useful as well.

Due to the lack of some resources, I was asked to create an NFS server on Solaris. They figured all *nix flavors are alike and I should be able to do it. I was able to get it running, especially due to help the SunHelp NFS FAQ . I still have an unresolved issue concerning mountd ... That daemon keeps getting killed on the NFS server which results in no client being able to mount NFS shares any longer. *sigh* Update: turns out Local Zones cannot run an NFS server. Only the Global Zone (on a physical host) can have an NFS server. Other zones can use an NFS client to connect to it, even from other physical hosts. Alternatively, you can replicate NFS shares between physical hosts in the Global Zone and use clients to connect to it. Or loop back to the Global Zone from the Local Zone using LOFS.

I just came across this: Configure BASH, KSH, TCSH, ZSH Shell To Logout User Automatically After Idle Time . I was looking for that months ago but couldn't find it. Then I forgot about it, until now! All you need to do is set and export an environment variable, which can be set system-wide in /etc/profile !