Archive for March, 2009

On Linux RAID and LVM

Sunday, March 29th, 2009

In an earlier blog entry on how we evaluated various virtualization technologies, I also wrote about using Linux Software RAID (md) instead of FAKERAID/HOSTRAID.

RAID as most know it is a technology that allows the grouping for multiple physical hard drives into one logical drive for either redundancy, performance or both. But the technology is not without caveats.

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The Cost of High Availablity

Saturday, March 28th, 2009

So here I am once again sitting in a meeting room of an ISP with some 4 or 5 executives, salesguys , product guys and a bunch of other engineers discussing how we should set up HA. The entire project’s network was drawn up on a white board and three engineers stood by the sides. They were pointing at every link and node in the diagram and asking, “is this HA?”

You’d be surprised how long these discussions can take. It went on for about two hours and one dude finally broke the tension and stood up, and we thought he was headed for the washroom but he said instead, “what’s the point of all these? With all these costs, will the service even sell?”

He hit the nail. The room was quiet for a moment.

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The Crisis of Credit Visualized

Tuesday, March 24th, 2009

Non-tech related, but affects everybody. This is a great video explaining the credit crisis. If you can’t see it, go here.


The Crisis of Credit Visualized from Jonathan Jarvis on Vimeo.

VMware ESX 3i, VMware Server 2.0, Citrix XenServer or Sun xVM VirtualBox?

Wednesday, March 18th, 2009

With our growing customer base and usage, Securlogic just purchased another Sun Fire X2100. The shipment arrived on Monday and I have been running around town trying to loan a USB keyboard and struggling to get the box to boot off a USB disk. ESX 3i simply refuses to boot so I got it running with a copy of CentOS 5 (LiveCD) using the Fedora Live USB Creator. Lesson learnt - keep a USB keyboard or a USB to PS/2 converter near you and don’t buy a server without a DVD drive.

Meanwhile, the virtualization infrastructure is due for an upgrade (we’re still on VMware Server 1.x). I’m evaluating VMware ESX 3i, VMware Server 2.0 (on CentOS 5.2), Citrix XenServer and Sun xVM VirtualBox and I’ll just drop a few quick pointers for those who are going though the same process as I am.

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Recycling The Internet’s Bandwidth

Tuesday, March 3rd, 2009

I was chatting with a guest from US the other day and he brought up an interesting point. In many countries like Singapore, the Internet is the only common household utility that charges a flat fee and we could use as much as we wanted. Pretty much all around the globe people still pay a unit price for power, water, gas, TV and phone.

So what makes the Internet different?

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