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.
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.
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.