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Showing posts from April, 2008

Simple Steps to Improving Availability - Five Essential Transitions

A poorly managed high availability cluster will have lower availability than a properly managed non-redundant system.

That's a bold statement, but I'm pretty sure it's true. The bottom line is that the path to improving system availability begins with the fundamentals of system management, not with redundant or HA systems. Only after you have executed the fundamentals will clustering or high availability make a positive contribution to system availability.

Here's the five transitions that are the critical steps on the path to improved availability:

Transition #1:From ad-hoc system management to structured system management.

Structured system management implies that you understand the fundamentals of building, securing, deploying, monitoring, logging, alerting, and documenting networks, servers and applications, that you have those fundamentals in place, you execute them consistently, and you know all cases where you are inconsistent. Ad hoc system management doesn'…

Virtualization Security - Reading List (update)

(Added and updated links) Here's a reading list of interesting posts in the virtualization+security space. There is a lot of thought going on about how virtualization in the data center affects application security. If you have VM's, you ought to be reading and thinking. Really thinking.Start with Five Immutable Laws of Virtualization Security. Follow through to the Burton Blog for details. (Pete Lindstrom, Spire Security)Maybe read “Virtualization and Security: The Full Story” (I'm still thinking about this one.) I'm done thinking. See comments. (Sara Peters, CSI)Thoughts on auditing virtualized environments, separation of duties, and audit controls. Are your auditors going to declare all the vm's that share the same hardware cluster in scope for the audit of one of the vm's? Ours will. (Hoff, Rational Security)Bits on PCI compliance (Hoff, Rational Security)The operational issues surrounding virtualized servers, or - how are you going to manage the siloed ope…

ARS Technica Articles on Commodore Amiga

Jeremy Reimer of ars technica is running an interesting series of articles on the birth and death of the Commodore Amiga.

It handled graphics, sound, and video as easily as other computers of its time manipulated plain text. It was easily ten years ahead of its time. It was everything its designers imagined it could be, except for one crucial problem: the world was essentially unaware of its existence.
We pretty much laughed at the primitive video capabilities of 1985-1990 Mac's and PC's as compared to an Amiga. Those two platforms were pathetic. And when we combined a $1500 Amiga with a $1500 Video Toaster card, we had a decent video editing machine nearly as functional as dedicated editors costing far, far more. My guess is that few people today realize how far advanced that computer was compared to its contemporaries, and how long it took the rest of the industry to catch up.

I use Windows Movie Maker and iMovie to play around with video, and other than the vast improvements …

Ad-Hoc Versus Structured System Management

Structured system management is a concept that covers the fundamentals of building, securing, deploying, monitoring, logging, alerting, and documenting networks, servers and applications. Structured system management implies that you have those fundamentals in place, you execute them consistently, and you know all cases where you are inconsistent. The converse of structured system management is what I call ad hoc system management, where every system has it own plan, undocumented and inconsistent, and you don't know how inconsistent they are, because you've never looked.

In previous posts (here and here) I implied that structured system management was an integral part of improving system availability. Having inherited several platforms that had, at best, ad hoc system management, and having moved the platforms to something resembling structured system management, I've concluded that implementing basic structure around system management will be the best and fastest path to…

Asynchronous Information Consumption - Random Thoughts

We spend lots of money on various forms of asynchronous media converters. People seem to be moving their media and information consumption habits, and perhaps even a portion of our social habits, toward asynchronous, store-and-forward type mechanisms.

I find the shift to asynchronous consumption interesting. When time independence is combined with the location independence that comes from being un-tethered, a fundamentally different lifestyle results.

Interesting examples, in no particular order:

DVR's convert synchronous media into asynchronous media. I find it wonderfully ironic that we send film crews to deserted islands for weeks, filming ordinary people doing un-ordinary things to each other, send the film back to a studio, where several months are spent slicing it up and gluing it back together to make it somehow more dramatic and presumably more watchable, then synchronously spew it out over the air every Tuesday at 8pm to an audience of twenty million people who are leaning…

Solaris Live Upgrade, Thin Servers and Upgrade Strategies

Sun recently upgraded Solaris Live Upgrade to permit live upgrades of servers with zones, and from what I can tell, seems to be positioning Live Upgrade as the standard method for patching and upgrading Solaris servers. This gives Solaris sysadmins another useful tool in the toolkit. For those who don't know Solaris:
Solaris Live Upgrade provides a method of upgrading a system while the system continues to operate. While your current boot environment is running, you can duplicate the boot environment, then upgrade the duplicate. Or, rather than upgrading, you can install a Solaris Flash archive on a boot environment. The short explanation is that a system administrator can create a new boot disk from a running sever (or an image of a bootable server) while the server is running, then upgrade, patch or otherwise tweak the new boot disk, and during a maintenance window, re-boot the server from the new image. In theory, the downtime for a major Solaris upgrade, say from Solaris 9 to S…

System Management by the Least Bit Principle

System Management Principle Number 6:
If you remove one more bit, the system will fail.
Minimal installs, when applied to systems, result in systems that have higher security availability.

This isn't new. This is just a restatement and perhaps an extension of normal securing and hardening of systems. The following are examples of how to apply least bit to various parts of your systems and applications.

File System Permissions (rights) are least bit when removing one more role, right or permission results in a failed application. The goal is to minimize permissions, either by starting with no permission bits and adding permissions until the application is fully functional, or by starting with a best guess on permissions and removing rights & permissions until the application fails. Ideally the vendor would have tested and configured the minimum permissions and rights for the application.

That rarely, if ever happens. The best example I've encountered is a couple decade…

Privacy, Centralization and Databases

A fascinating article on the potential problems associated with privacy on a large government run database was recently posted at ModernMechanix. The article appears to be in response to an effort to build a centralized data center that would contain personal records on US citizens. The interesting part is that the article appeared in The Atlantic in 1967. Reading it today makes it clear that not only did the author, Arthur R. Miller, laid bare the fundamental issues surrounding centralized government managed data repositories, but that the issues neither have changed, nor been addressed. Unfortunately the article is probably far more relevant today.

The author is concerned that:
With its insatiable appetite for information, its inability to forget anything that has been put into it, a central computer might become the heart of a government surveillance system that would lay bare our finances, our associations, or our mental and physical health to government inquisitors or even to cas…