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You can get 99.999% uptime at commodity prices.
Getting 99.999% uptime for servers is difficult.The classic five 9s means a server can only be down for 5 minutes or less for the entire year.
There are servers that can do this, but typically you have to pay a steep price ($200,000 or more for proprietary solutions). NEC offers a server with off-the-shelf Pentium III processors that promises 99.999% uptime for about one-tenth the price (around $20,000). We tested the NEC Express5800/320La and found it a fantastic minimal downtime server, if you're willing to trade off some performance for the commodity price.
Clustering vs. redundant
High-availability server systems come in two categories: server clustering and hardware redundant servers.
Server clustering uses inexpensive commodity servers that communicate with each other to determine when a server in the cluster is down. When a failure is detected, the standby servers pick up the load.
The switch times during failure tend to take a while because the cluster management mechanism has to determine that a failure has occurred, notify the standby server, and then let the standby server take over.
The second category hardware redundant servers, contains fully redundant components that can be hot-- swapped when a component fails. Each standby component stays synchronized with the active components to minimize the switching delay in case of an active component failure. The good news is redundant hardware is simple to install, manage and maintain because the hardware does the work. The bad news is all this custom hardware adds up to an expensive server.
The Express5800 falls into the hardware redundant server category but instead of using expensive proprietary components, it uses off-the-shelf Pentium III processors and off-the-shelf RAM.It has fully redundant subsystems - redundant processors, RAM, PCI slots, disk controllers and disks -- available for the approximate price of two commodity servers in a cluster configuration. However, the Express5800 only supports Windows 2000 Advanced Server, which comes bundled with the box.
Features
The Express5800 is a little wider and heavier than the average server.The rear panel gives access to two power supplies that are hot swappable, redundant and can balance the load. You can also access a console panel,which has two Universal Serial Bus (USB) ports (for the keyboard...