What a PITA!!

This week I've been configuring a couple of new HP servers, ProLiant DL 360 G6s to be precise. They were configured to have 8 internal disks so the internal CD/DVD-ROM had to be sacrificed.

So to configure them, I temporarily attached a USB CD_ROM drive, Keyboard and Mouse and attached a monitor.

Having installed the latest CentOS x86_64 Linux from CD on the first one, I removed the CD-ROM and rebooted. It hung coming up configuring the USB storage driver!

So I spent a day googling for help. I re-installed Linux half a dozen or so times. I downloaded the DVD and followed the instructions to make that available via both HTTP and NFS and tried using the first CD to boot from and then installing across the network. Actually that was considerably faster than the CD method!


Nothing changed the hang during boot. Always on the USB storage driver installation.

As a punt with nothing else to lose, I unplugged the USB keyboard and mouse and rebooted.

The b*$#*^d box booted all the way.

I plugged the keyboard in and it was recognized without fuss and was immediately useful.

So it goes! Some days are just like that.

Downsides of Virtualisation?

This post possibly falls into the "stating the bleeding obvious " category! However,...

Reducing server count isn't just about reducing the amount of hardware. But, if you have virtualised a bunch of servers will you be so keen to look into combining their functions?
There still can be value in combining the functions of two virtual servers. There are the management benefits of fewer servers to manage and if you have software that is licensed on a per server basis, then there will be financial benefits too.

Eventually, you will develop an architectural dependence on servers that are virtualised. If your mail relay is virtualised and your payroll system isn't, then should your payroll system need to send email, a lot of the infrastructure needed for your virtualisation environment will need to be up and running too.
In most cases the virtual environment will be up and running. However, there are periods when you may be recovering from a disaster when that isn't the case.

Are these reasons not to virtualise?

Of course, not!
But they are factors to consider and factor in to your decision making.

Webmin Usage

I almost called this post "Deskilling in IT #2", but I've changed my mind. My previous blog about deskilling dealt more about my change in attitude to the way to build and deploy customised server. With this blog it is really the manner in which the web interface is an enabler of complex server configuration without knowledge of the underlying command line options.

To set the scene, I had an rPath Mediawiki appliance which was configured to provide 4 separate wikis. The conary package management system had stopped working some time ago.- possibly something I did - and every now and again was filling up the / partition (the only partition). I couldn't add SNMP to it - well not easily. So remote management was fraught!

To resolve the issues, I built a new CentOS Linux v5.4 server with Apache and MySQL installed; configured SNMP so it could be added into our Zenoss monitoring system; copied the last night's mysqldump backup files across to the new server; copied the webpages across; copied the appropriate .conf files to /etc/httpd/conf.d/; installed webmin.
Through webmin, I then:

• created new databases for each of the wikis;
• added the individual database users for the wikis;
• added the database access rules for each of the database users
• loaded the tables and data from the previous nights backup
• started the Apache service

All that took only a few minutes. And it was up and working.
Obviously starting the Apache service was simply a "service httpd start" with possibly a "chkconfig httpd on" beforehand.
The database actions are not beyond my wit to discover, either by reading the documentation on the MySQL website or indeed in terms of going through the source code for webmin and the mysql module. But with webmin, I did not have to either look them up online or in my notebook.

Perhaps, the only thing that seemed to be harder to configure through webmin is the iptables based Firewall. I much preferred to just edit the /etc/sysconfig/iptables file and enter service iptables restart. Myabe that is because generally, the edits I make are pretty simple involving only copy and pastes of lines and then just changing the port number.

Webmin makes it easier to administer many parts of *nix systems if you already know what you are doing. If you do not know what you are doing, it is just as difficult as previously.

I like webmin's facility to create links from one webmin installation to one or more other installations. My zenoss server is also a ssh jump server to other *nix systems, particularly those in the local DMZ. Making it also a console for the webmin consoles is just a logicial next step. Although to increase security even further, I'm considering tunnelling the access to the webmin port 10000 though SSH.

vReference Card

The excellent VMReferemce Card site has been updated for v4 and now has the URL: www.vreference.com.

As well as an updated VMware reference card there is also a reference card showing all the ports used by various VMware services, which has been called the firewall card.

I am especially pleased to see the firewall diagram. The firewalls are controlled by a separate team at my company and they are not always the most flexible of guys. Haha. Every change to the firewall has to be raised on a form, signed off by Directors and/or VPs, and faxed through to the corporate HQ, where it is saved in a DB. All that before they do anything. Occasionally they'll actually help out testing what is actually needed, but generally they are a PITA.

Most of the ports are indeed documented within Manuals. However, certainly with the Vi3 documentation, I was disappointed by the quality of that documentation. Ports would be listed at required with the inference it was only one way and solely one of TCP or UDP. Unfortunately, some experimentation demonstrated that that might not actually be the case. A port needed to be open in both directions, TCP in one direction and UDP in the reverse!

Anyway having all that information so clearly documented here will be a great help going forward.

That's that!

VirtualBox Shared Folders

Shared Folders on VirtualBox would be fantastic if it wasn't such a PITA to access them the first time on XP.

Setting one up is easy, but accessing it is something else. At first I thought they weren't working on XP. Indeed others have come to the same conclusion!

Some quick googling brought me to the following blog. Huzzah! A solution. 

Now, carefully click on the expand icon () right next to My Network Places. Make sure you click exactly on the expand icon. If you accidentally clicked on My Network Places, you ruined everything and you will have to go back and start all over again.

I'm not sure what the difference was thought to be by Microsoft design team. From a user perspective I'm struggling to think of anything else I would want explorer to do for me at this point. Perhaps one of the team has blogged about it, but... Well, now I know.

Given the age of the blog the documentation ought to be considerably clearer than it is.

So it goes!

Linux Magazines - the March issues

Not a particularly good month for either magazine. Although to an extent for any topical magazine it is acase of working with what you have.

The DVDs provided by the magazines were surprisingly similar:

LinuxFormat: Slackware 12.2, OpenSuse 11.1 & Mint 6

LinuxMagazine: Slackware 12.2, Fedora 10

Personally I only found a couple of interesting articles across both magazines.

LinuxFormat had an article about GIT, and the ext3cow filesystem.

LinuxMagazine had an article on parallelizing bash  scripts, the Conky system Monitor and Debian's Fully Automated Installation mechanism.

I have to say that FAI was remarkably similar to Sun's Jumpstart technology.  Which is a good thing. Jumpstart is a really useful tool. Of course there should be similarities as they are trying to do the same thing, if for different OSs. 

Whilst LinuxFormat dedicated 4 pages to GIT, whereas LinuxMagazine had a three inch column referring to David Howell's The Git Hater's Guide to the Galaxy - which shows a little pretention. Or perhaps was an attempt to indicate the level of humour the author was attempting to inject into the dry subject of software configuration management.

Conky is perhaps most similar to Windows Taskmgr. Until this article it hadn't occurred to me that I didn't use such a tool when I run Linux desktops, but it is usually the first thing I fire up, if I haven't already added it to my startup, on Windows.

ext3cow is an interesting development, mirroring the UFS snapshot facility on Solaris. I'd like to really look at ext3cow in much more detail though before considering using it to replace the NetApps at work.

And that's that!

Vista As A Virus #2

At my company, Lotus Notes is stored on the D:\ drive @ D:\notes with the id file and various nsf stored in D:\notes\data.

Except if you have Vista as your OS.

On Vista, although you tell Notes to use D:\notes\data it will actually use C:\Users\App Details\Local\VirtualStore\IBM\notes\data

Why is it like this?

Because Vista could!

Because Vista is a Virus!

This might not seem such a serious problem. Unless you are using Notes on more than one machine and need to copy the id file between them. And then you have to go in search of the files.

Yes, that is a one off operation. But why the heck should you need to search?

Aarrgghh!!

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.

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".

Vista as a Virus #1

Among many other duties and responsibilities, I am also a Domain Admin of my company's Active Directory. Despite having a normal user account, I must confess to frequently logging into my desktop with my Domain Admin account. On one such occasion, I was trying to track down a DNS issue that our Sydney office was suffering, when I realised that I needed to flush my local DNS resolver cache. Pretty straight forward? Just open a Command Prompt:

C:\>"ipconfig /flushdns"

The requested operation requires elevation

C:\>

Oh! That didn't work! What the heck is "elevation"? Other than sounding like a U2 song!

Well, having googled around and found this thread on a Microsoft site, it appears that as an Active Directory Domain Admin I was insufficiently priviledged on my Desktop to perform that operation from a Command Prompt!

To be able to perform that sort of operation in a Command Prompt I should have started the Command Prompt with "Run as Administrator".

Some may argue that this is merely improving security, but I would not be one of them. Since then, I was started up FileZilla which informed me there was an update available and did I want to install it. I said yes. FileZilla downloaded the file successfully, and then failed. Guess what! Actually running the install program was an operation which required elevation. Grrr!

Suppliers' Websites

If ever an application crashes on Windows, I never hit the button to send information about it to Microsoft. I guess I was conditioned in the futility of attempting to engage Microsoft Support over 15 years ago. Ever since I haven't bothered with them. There is only so much hitting your head against a brick wall that is good for you after all. That said in this age of the Internet the resources provided on Microsoft's website are pretty good. Even the things that I might want to see might be there. If only I could find them.

I remember possibly 10 years ago, a colleague slamming the phone receiver down in frustration after talking to IBM when trying to get a licence for some software we had purchased. I took over and finally got a licence. I wasn't completely sure it was "our" licence, but it was a licence and it worked and we were able to move on. Even after its recent re-vamp - actually I'm sure that it is probably a continuous process in play here - it is still damn difficult to find what you really want. Try and use the IBM search for the bios update for a specific server, e.g. a x346. The results will list just about any IBM server.

The solution?

Just use Google. We all know it makes sense. I just wish for a higher signal to noise ratio. But no matter how bad it is, its still better than trying to use these two Vendors own search engines.

Deskilling

13 or so years ago, when I first started at my current company, I would cheerfully jumpstart a server to an appropriate Solaris OS revision, download the source of an application, build it, install it and configure it as needed.

Then sites like sunfreeware came online. And the order of business became, jumpstart the server, download the application, install it, and then configure as needed.

Recently, it has been a case of "I wonder if there is a VM to do that?" Lets download that and configure it.

Software Patents

Patents can protect a company's ability to be in or stay in a market. They can also keep out a whole bunch of new starter competitors, which might be equally important.

I've recently come across a software patent applied for and granted to a former work-colleague. Not from my current company, I hasten to add. No names. No pack drill!

I read the patent application. And I've thought about it for a while.

Was it obvious? Completely!

Is there oodles of prior art? I'm sure of it!

Is it enforcible? Given the previous two answers, almost certainly not!

Are software patents a complete waste of everyone's time? I think they probably ought to be. Unfortunately, I suspect they will still be around for some time.

ldap services

One of the prime requirements of any service that is added within my company is authentication.

Within my company, there are two main sources of authentication:

• Microsoft Active Directory
• Lotus Notes ldap service

Now it is possible with varying degrees of difficulty to "persuade" most tools/services to use LDAP as an authentication source. However, there are assumptions written into most of these tools that if you are seeking to use LDAP you are either using OpenLDAP (or similar) or Microsoft's Active Directory.

In some ways it is quite encouraging to see how many other people are looking to authenticate against Active Directory. In other ways, it is deeply depressing that with so many years head start, the various UNIX vendors couldn't agree upon a common naming services standard that would be an improvement upon Active Directory.

I suspect that some will point to Kerberos and LDAP themselves as collaborative triumphs, which Microsoft had to use within Active Directory itself. However, whilst those are compelling technologies, they are not themselves individually a compelling solution. Collectively, they can be induced to become a solution, but depending upon the implementor, they may not be a compelling solution.