When was the last time you tested your backup computer system. Your backup will not work. The sooner you test your backup the less chance there is of your primary system failing.
When your backup system works, your primary system works. The primary system will fail after your backup fails or your backup system is no longer compatible. This is not unusual. Here are some reasons why backup systems are less reliable than regular computers and why, on the first time you really need your backup, your backup will fail.
They are not identical
I have two machines. Identical models purchased in one order. They have different BIOSes. One works. The other does not. Both worked when first tested. I added hardware to the primary machine without problems. When I tried to make identical upgrades to the backup, the backup had an incompatible BIOS. I updated the BIOS in the backup but it still was not compatible.
If you think that is unusual, talk to people with experience. I worked on a project where we were going to buy a thousand identical machines. We asked the preferred supplier to send us three identical samples right down to the BIOS. When we tested the first two machines, both from the same batch with consecutive serial numbers, one had an up to date BIOS and the other had an old version of the BIOS. We opened up the third computer, again from the same batch, and the third one had a different motherboard. You could not use the same BIOS on the different motherboard.
One of the people working on that project later reported the same thing happening across most of the suppliers who sent in samples. Lots of people working on other projects report the same type of problem. One customer had a floor full of Dell computers all delivered at the same time for the same order. Some of the computers had usable keyboards while the rest had inferior almost unusable keyboards. Some of the computers were fast enough for typing full speed in a word processor while others were barely fast enough to type into a simple text editor. Some of the computers fell asleep for seconds at a time. Many were reported as defective. Engineers inspected, tested, and may have changed parts. None of the computers improved.
manufacturer in America is unable to make the real manufacturer, the one in China, use the same parts for several consecutive computers, what chance do you have of buying identical computers further down stream where different batches are mixed and the best you can hope for is a similar model number?
There are lots of BIOS settings that trip you up. Take the SATA Type settings as an example. You can choose
Legacy IDE, or
AHCI. AHCI does not work with older operating systems, does not work reliably with recent operating systems, and works with most new operating systems. In the Windows series, it does not work prior to XP, works with XP only with a special action, and works with Windows 7. Nobody uses the disastrous Windows Vista so lets not talk about Vista.
Think of two systems with XP. You cannot use AHCI when you install XP. After you install XP and apply all the drivers supplied by the motherboard manufacturer, you can use AHCI. You will occasionally need AHCI for some strange combinations of hardware and software.
It is easy to switch your primary system from Native IDE to AHCI and forget the backup. You add hardware, there is a problem, and you test some changes including the AHCI change. You forget to replicate everything on the backup. When the primary dies and you move your system disk from the primary to the backup, the system disk will not work.
There are additional tricks to confuse you. When you switch between the two SATA types, you can add or reformat disk partitions. Data partitions work either way. Your system partition will fail if it is accessed the wrong way. Now you are stuck with the problem of not being able to move a disk from one machine to another. You could copy a partition from one machine to the other but they both have to be working and it is too late for that.
How do you avoid those types of problems? Make all your disks RAID 1 so you can split the two disks and test with one while continuing to run with the other. Make only one change at a time so you can identify and reverse out the change that kills your system. Test your recovery procedure after every hardware change and operating system update on the primary system. Keep all your data off the system disk so you can abandon your system disk and build a new one.
The computer you use every day will dry out each day when you switch it on. The backup will absorb moisture and corrode. In cold and damp climates, use your backup computers on a regular basis.
Make sure all the firmware is the same. This includes the BIOS, your ADSL firmware, the stuff in your router, firewall, any NAS devices (Network Attached Storage), and backup devices.
You have all sorts of critical information online. You buy the best cable access. Cable breaks just like everything else. You could convert your telephone land line to ADSL as a backup. When a tree branch kills your cable, it kills your land line and ADSL. Get wireless access to backup the backup.
Your office catches fire and you run out the door with a backup CD but then have to spend days locating a new computer and installing all that software. A cheap notebook computer can backup your powerful desktop. Sure, the screen is not as big and the disk is pathetically slow but at least you are afloat while you rebuild.
Did you put everything online?
Every sales person tells you to dump your computer and use Web based applications. Yeah, try it. Now let your city flood, go through a bushfire, or sink in an earthquake. Now try to work from online.
Take the example of Sydney, Australia having a major problem and five million people moving to other cities in Australia. There is accommodation for less than a million and spare computers for few than half that. Among the few that can access the Web, how many have their complete list of Web sites, user names, and passwords with them? What do you do if your Web site is hosted in Sydney and is now dead? How would Australia access the Internet given the fact that the top two international submarine cables, the bulk of our Internet connectivity, is through Sydney?
Everything online needs a backup system and the same constant testing as a local machine. When the sales person tells you they have tested all that and have there own backups, remember the following well tested consumer advice.
If the sales person is breathing, they are lying.
Online systems are only safe against a known threat if the online system provider provides a written guarantee with clearly stated financial penalty if they fail to deliver within a specific timeframe and you can successfully get the money. Under the terms of the Australian-American free trade agreement, trade is free only for Americans, it is financially impossible for Australians to recover anything from American suppliers. Most other countries are worse.
If any part of the online system is outside your own country, you cannot take practical legal action for an affordable price. When they screw up, you just have to give up and go broke.
I am not talking theory here, lost of access kills businesses and sends people bankrupt. The first well publicised case was in 1993. It is a known problem and explains why all those online systems have so many pages of exclusions in their agreements. When one of those data centres dies, you will be customer number 7398 on their to-do list. You will find out that they have 560 call centre staff in India but only 6 in the computer centre in California and 5 of the 6 were injured in the earthquake.
Today one of my desktops died. The power supply went up in a puff of toxic fumes. The backup would not work because of a firmware incompatibility. The hardware is identical. The BIOS is identical. The setting are documented and identical. Somewhere there is an add-in card with different firmware. If I remove all the add-in cards, the backup will not be usable for all tasks.
The second backup was temporarily changed to for a test of something new and changing it back will take more than a day because it started as slightly different hardware and has a completely different BIOS. To be exact, the BIOS appears to have the same settings but with different names under different menus to the point where it often takes hours to find compatible settings for really minor changes.
The third backup is half assembled. It donated some of the parts for the experiment on the second backup and I have not yet purchased the replacement parts. I am facing a day of driving around to get the bits missing from the third backup. Looking back, I should have purchased extra parts for the experiment and left the third backup untouched.
I am currently working from that cheap notebook backup that I kept as the backup of the fourth kind. It is not really cheap, it is a high end notebook but is slow compared to my primary computer and uses those little rotating magnetic disks that are Oh So Last Year and very slow compared to my SSDs. productivity is down.
The screen on my backup notebook is big for a notebook but less than half the size of my desktop. I can look at only one page at a time. Productivity is down. Is your backup workable?
Lots of companies spend money on backup computers but not backup printers, scanners, modems, cash registers, or anything else. Could your business survive with a bunch of people sitting at computers they cannot really use because they do not have their other tools of trade. If a person uses a scanner for the start of a critical process, they need a scanner with their backup.
A good way to test a complete backup is to switch over for a day.
In my case I have very little connected to my computer but there is a lot of hardware connected to the network connected to my computer. A backup computer is almost useless without a backup network. I have the wired network working from the same base router as the wireless network. I am about to duplicate the routers with one powering the wired network and the other the wireless network. The desktops will all get wireless add-in cards to keep them going if the wired network fails. The notebooks already have both wired and wireless.
Paranoia is stressful and unhealthy so hire someone else to be paranoid for you. Bring in a consultant to worry about your complete disregard for safety. Freak him or her out with stories about how you carry your customer list around on your notebook unencrypted. Then listed to his or her tales of doom and gloom then do something about a usable working backup.