SCM @ home

I've started a project at home - homework if you will. It will require both database design and and web programming. As with many others projects, I'll use MySQL as the target database and PHP as the web language. I'll possibly also create a client, perhaps utilizing mono, or maybe just Perl/TK.

I decided to use an SCM. It was going to be Accurev, indeed the title of this post was originally going to be "Accurev in Anger." However, I've just checked out the Accurev website. Apparently the previous 2-person free download is no longer available. I checked out the websites of a number of other SCM vendors: PureCM, Perforce, PlasticSCM and IBM (for ClearCase and Team Concert.) Perforce appear to be the only company still providing that kind of long term small scale evaluation without requesting the inside leg measurement of your Mother's first cousin's girlfriend's sister's hairdresser's cockateel. Well, in addition to ClearCase, Perforce is also used at work, although not by a software development team. I do not want to use it at home.

Consequently, it looks like I'm going to be using Open Source. Well, there's quite a choice of those too. Might as well be Subversion with the TortoiseSVN client. Bazaar or Mercurial or Git might have been more "with it" or edgy or out there, but as its just me the initial attraction is to actually get things done.

I've downloaded and installed the server and client. Now to start writing some code.

Solaris Virtualization - LDoms

My intention was to make this post a cookbook for Solaris virtualization with LDOMs.

However, that is unnecessary. There are some excellent online resources already.

There is an excellent beginners guide on Sun's website.

And an excellent cookbook, which is also on Sun's website.

The OpenSolaris website includes a good list of resources. As does BigAdmin.

It's all good stuff!

Solaris Virtualization

I'm doing quite a lot with virtualization at work. I've recently been looking at virtualization of our Sun Sparc servers. Sun has a very good story on virtualization. Sun has positioned itself to cover the entire virtualization market - with some very good software. Sun's strategy, which in fairness is similar to many other vendors, i.e. VMware & Microsoft, has been to make the hypervisor or "VM player" free and to charge for the management software.

Sun's virtualization software encompasses:

• LDoms
• Zones/Containers
• VirtualBox

LDom are similar to VMs under VMware ESX.
Zones/Containers are similar to VMs on VMServer
VirtualBox is, for me, more intuitive than VM player/workstation. At least in the current version.

There is a lot of information out there on the web about Sun's virtualization. The OpenSolaris and BigAdmin sites are good starting points.

Over the next few weeks I'll be creating a cookbook of procedures for using Sun's virtualization. Some of these I found on the Internet and am reproducing for my own benefit to have in a single place. Others are the result of my own perspiration.

Darik's Boot and Nuke

I came across Darik's Boot And Nuke (DBAN) a couple of months ago. I'm probably late to the party here, but I just wanted to say it is fantastic. It does exactly what it says on the tin!!

All I had to do was:

• Download the iso image.
• Burn the disk.
• Put the disk in a PC.
• Boot the PC.
• Accept the defaults.

Result: a wiped PC

It fulfilled my requirement and best of all it was free.

Linux Magazines

For the longest time I had preferred Linux Format. But the latest issue of Linux Magazine was really useful. At least for this month's edition I prefer it!

The Linux Magazine introduced me to new software that I had previously not heard of. Also, it seems to have caught up with the latest distributions. Previously it always seemed to be two or three months behind the times. But this month it has Ubuntu 8.10 at the same time as Linux Format!

The review of Virtual Machine management software was timely. I'm heavily involved in virtualization of Linux, Windows and Solaris (both x86 & Sparc) systems. I had been unaware of the software reviewed. As I've used UNIX for approx 25 years, the command line nature of the most interesting tool, MLN, won't worry me, but for SysAdmins who have only ever used the Windows interface of VMware Virtual Center server or the Virtual Infrastructure client (the "Click Next to continue" generation - or to be ruder lets call them SysAdmin Lites!) it will probably seem quite daunting.

The review of the O'Reilley book "Python for Unix and Linux System Administrators" was interesting. Although why anyone would want to use Python, when Perl is not only available but frequently seems designed for the job, is a mystery to me. Thats probably 13-ish years of prejudice coming to the fore!

The regular SysAdmin section is also usually very useful. This month's feature on Siege was particular interesting. I'll be looking into seeing if I can use that.

The websites for both magazines closely reflect the characters of the magazines themselves. The site of Linux Format is flashier, but the content of Linux Magazine is more detailed. Which sort of reminds me of a report I heard about about 15 or so years ago. The professors at an University examined the quality of thesis produced by their students. The best work from an academic point of view was produced by PC users. Mac users spent too much time chosing the just the right font or font size or slightly tweaking the layout and so didn't have enough time for "thinking".

Software configuration management software

I've been using ClearCase for approx. 13 years. I've been there, done that, and got quite a few Atria, Pure Atria, Rational and IBM T-Shirts over the years. Not to mention a few conference rucksacks and even a pint glass! Just recently I was reading Linux Magazine and read about another new software configuration management (SCM) tool, PureCM. Which interested because...

I was at an IBM seminar recently and saw some presentations about Rational Team Concert (RTC) for the first time. I was reminded of a bunch of presentations given 6, 7 or 8 years ago by Rational/IBM - my account manager at the time had told me that they were going to consolidate their tools so that there would only be a couple of tools left. Everything went quiet for such a long time I thought that the idea had been shelved or that someone had realized that having half a dozen to a dozen point tools at a slightly lower price would generate more revenue than a couple of more expensive tools. So it does now look like ClearCase, ClearQuest, ReqPro and a few other tools have now effectively been superseded by RTC. Although you can plugin ClearCase, ClearQuest and ReqPro to RTC the best reason I can think of for doing so is to ease the migration to the new tool.

So given that you are going to start again with a new tool, why not play the field and see what else is out there.

If you are going to pay for the tools then the two SCM tools that I would consider in addition to Team Concert would have been Accurev and PlasticSCM.

I've long wanted to actually put Accurev through its paces in anger. Its implementation of streams is far superior to that of ClearCase UCM, which can be considered some sort of half-*rsed after-thought. Although UCM has gotten smoother recently. From friends who have used Accurev in anger, I've heard that it does enable multi-site use of a single branch without resorting to some of the nasty hacks that have become second nature to ClearCase old-timers. The reduction of merges and regression testing builds that must provide might well be sufficient to consider or investigate a migration.

The feature of PlasticSCM that first caught my attention was the security model, which again was far superior to that of ClearCase. ClearCase, and DSEE before it, were designed by old time UNIX engineers and so utilized the octal user, group,others builtin permissions. PlasticSCM utilizes ACLs, like you'll find in Active Directory, which can be applied to almost any item: elements; streams/branches; individual versions; labels; etc. So much more flexibility.

But looking at the documentation for PureCM, it looks like it might be an acceptable alternative. Given that the tool apparently runs on Apples OS X, Linux, Solaris and Windows it is interesting that the feature comparison they chose to make was with VSS. I suspect that Windows may have been their most successful platform to date. The changeset functionality seems similar to that of Perforce. The builtin issue tracker is similar to Trac. The plugins for CruiseControl and FinalBuilder (a new tool for me - one I'm going to have to take a look at) are also a step in the right direction as RTC has built in build management - actually rather sophisiticated build management.

I do not have a conclusion. There isn't a prescription that all can take. Which is one reason there are so many SCM tools out there. This article is really another starting point for further blogs I'll be writing.

Dimdim

Very impressive software. Shame about the name. I mean, you go to the CEO and tell him to use dimdim! In the whole Web 2.0 naming scheme of things, Dimdim is one of the oddest.

Anyhow, I downloaded the free VMware version of the software, which had been created for VM player, so I had to recreate the disk for ESX. There is very little configuration that needs or even can be done. Just the name of an SMTP server, which is necessary to enable meeting invitations to be emailed out! Of course, you have have to disappear deep into the directory structure to find the dimdim.properties file and <FX: Shock, Horror> open an editor to change the value. </FX>

My company's requirement for collaboration software which Dimdim came very close to satisfying will almost certainly be mirrored by many other companies. In the current economic climate, travel budgets are restricted and the ability to "meet virtually" over the internet/internal WAN would be regarded as valuable. So a requirement to try and save money whilst still enabling staff in disparate geographies to communicate face-to-face

How did Dimdim fail, then? Simply put, it was insufficiently configurable. Perhaps this is a fault of the free version. If it is, it isn't demonstrated elsewhere on their website. There is no configuration into an LDAP or any other naming service. So your CEO (or more likely his PA) has to remember the email addresses of everyone he wants to invite.

Another fault is perhaps the lack of adequate documentation.

The purpose of downloading the free version was to assess whether the company should consider the Enterprise version of the software. The inability to integrate Dimdim into the company's infrastructure really did for it.

Which in a way I guess also goes to prove the point made int this infoworld article. A couple of years ago, I was certain that "cloud computing"/"software as a service" was about to take over the IT world. Two years later, I can still see its potential to be a real game changer. However, the rate of change seems to have slowed considerable. Google's roll-out of new features seems to have slowed. Perhaps they are concentrating these days on reliability, availability, security, uptime and scalability. Which can be no bad thing.

From the point of view of the company I work with, there is a distrust of hosting critical systems externally. My company has a large Chinese subsidiary. Everything, all transfers between the China and anyway else, has to be approved by Trade & Compliance and IT Security. The Chinese R&D department is on a completely isolated network - no access to the Internet at all. Consequently, despite the attractions of some of the cloud computing applications available, my company would almost certainly not be able to deploy them. Dimdim included.