Number 240 - May 2003

Preventing Data Loss
by Brian K. Lewis, Ph.D. Member of the Sarasota Personal Computer Users Group, Inc.
Preventing data loss is just another way of saying, "Backup your hard drive". However there are many different ways to accomplish this. As we discussed in the March Tech Forum at the General Meeting, most people want a simple way to recover from a catastrophic hard disk failure. Unfortunately, in that discussion, I led some people astray when we were talking about using an external USB IDE drive. PowerQuest's DriveImage software does NOT work with USB drives. This fact is made very clear on their web site in the DriveImage FAQ's. About one year ago I tried to backup to a USB drive. In my case, DriveImage would not allow me to create an image file on the USB drive. Somewhere along the way this fact was reported in a software review in the Monitor and it just really slipped my mind. I guess it's just another manifestation of "old-timers" syndrome!    So, let's clarify just what DriveImage can do to help prevent data loss. DriveImage is primarily designed to create a compressed image file of an entire hard disk on either a separate hard disk or some form of removable media (CD-R, Zip or Jaz disks). The image file is one file containing all the contents of your hard drive including the operating system files. If this image file is created on a hard disk, the disk is not bootable. You can restore individual files, programs, or operating system from this image file. So, if your original hard drive fails, you have to restore to a new drive from the image files on the backup drive. Just remember the restoration process returns your drive to the condition it was in at the time you created the image file. The greater the interval between image file creation and restoration, the greater the data loss.    If you wish to have a bootable hard disk, you must use a program, which provides for a complete disk to disk copy without compression. The current version of DriveImage contains a DriveCopy program, which allows you to "clone" your hard drive. The "cloned" drive is an exact copy of your original drive and is bootable. However, it is not really recommended that you have two bootable drives installed in the same computer. This may lead to some problems in booting your system. PowerQuest recommends that you remove the "cloned" hard drive and store it in a safe place. Then once a month, reinstall the drive and make a new disk copy. In between these monthly backups, you should backup your data files to some media such as a writeable CD or DVD.    Using DriveImage to backup your hard drive is one system for preparing for the eventual failure of your hard drive. Admittedly, the life of a hard drive has increased greatly along with their increasing storage size. However, their warranted life span has been reduced. Several manufacturers have reduced their warranties from five years to three. This probably reflects the fact that few drives actually survive for five years. Consequently, if you don't prepare for the loss of a hard drive, you will lose everything you have stored on it when it does fail.    So what procedures should you follow in trying to prevent loss of information from a drive failure? Let's talk first about the ideal system. In this system you would have a second hard drive identical in capacity to your boot drive, generally your C drive. The second drive should be installed in a removable rack or drawer so it can be stored away from your computer. Then you should also have a CD-RW or a DVD writer. Using these media, once a month you would create either an image file or a complete copy of your C drive on the second hard drive. If your C drive is partitioned, then each partition should be copied to the second drive. Between these monthly backups, you should backup your data files using either CD's or DVD's. The frequency of these backups would depend on how much data you are willing to lose if your drive fails. If you only backup weekly, then you can expect to lose as much as one week's data. If you backup daily, then the most you will lose is one day's work.    So you say you can't afford to lose even one day's work. What do you do then? The best alternative is to use a two-drive system with a RAID system. RAID stands for Redundant Array of Independent Drives. This was originally designed for network servers using an array of SCSI drives. However, the technology has been adapted to use ATA drives (see my article in the November 2000 Monitor). An add-on adapter using RAID 1 mirroring can be installed in any computer running any version of Windows from 98 on. In a RAID 1 system, only two hard drives are needed. In this system the drive controller first writes data to the main drive and then writes the same data to the second drive. This provides an identical copy of the first hard drive. One disadvantage of this system is that the double writing of all data doubles the time required for disk access. If the software application is data intensive, for example database data handling, then there may be a noticeable delay due to disk writing. With the faster ATA 100 or 133 hard drives	combined with a fast CPU, this delay may not be noticeable. Disk reading may also be slowed unless the controller can read from both disks simultaneously. In order to install a RAID system you must have two identical drives and a RAID adapter card. Companies such as Adaptec and Promise make ATA adapters, to cite just two examples. Prices for these adapter cards range from under $50 to about $100.    With a RAID system, if one hard drive fails, the other can be immediately reset to be the master drive. The failed drive can then be replaced and the RAID system will rebuild all the information on the new backup drive. As with any two drive backup system, if both drives fail at the same time, you have a major problem. However, the probability of simultaneous failure is very, very small.    If you don't want to go to the expense of setting up a second hard drive and an adapter card, there is a software solution to the continuous backup. However, the software does not produce a mirrored drive. Instead, it monitors the data files and continuously backs up any changed files. This backup can be made to another hard drive, a second partition on your C drive or to any removable drive including a CD writer. V Communications and PeerSoftware make desktop software for continuous backup. These products are available from their websites for prices ranging from $29 to $89. You can also download free trial versions to see if this is software for you. Please note, I have not tested software from either of these companies. However, V the makers of System Commander, Partition Commander and other well-known products.    If you elect to use the data monitoring software, it would be advisable to use Drive Image, Ghost, or similar software to period-ically make a complete backup of your hard drive. In between these backups, the monitor-ing software would keep your data up to date. If you include a backup of your registry, you could be assured of not losing any program or settings information. This would entail more effort when you had to restore a hard drive. However, you would have far less chance of being caught without any backup at all.    One data area that frequently does not get backed up are the Outlook Express e-mail folders. These folders have different locations depending of the version of Windows on your computer. For Windows XP you need to back up these folders: (1) Documents and Settings\{username}\Application Data\Microsoft\Address Book; and (2) Documents and Settings \{username}\Local Settings \Application Data\Identities\{alpha numeric identifier}\Microsoft\Outlook Express. The italicized username and the identifier infor-mation in the brackets will be specific to your computer.    For Windows 98/ME the pertinent folders are: (1) Windows\Application Data\ Microsoft \Address Book; and (2) Windows\Application Data\Identities\{alpha numeric identifier} Microsoft\Outlook Express.    I don't really know the folder locations in Windows 2000, but I suspect it is similar to the locations for Windows XP. Windows NT used the same locations as Win98/ME. If you can not find your OE address book in any of these locations do a search for *.wab. That should locate your address book(s). To locate the folder containing your e-mail messages, run Outlook Express. From the menu select Tools, Options and then click the Maintenance tab. This has a button for changing the location of your messages. Click the "Store Folder" button and a small window will pop up showing you the location of your message folders.    The method you choose to handle your backup is not as important as the fact that you are doing backups. If you don't backup your hard drive, you can expect to have a drive failure and you will lose data and possibly some of your programs. Your daily mantra should be "Backup, Backup, Backup".    Dr. Lewis is a former University & Medical School professor. He has been working with personal computers for more than thirty years and can be reached via e-mail at: bwsail@yahoo.com or voice mail at 941/925-3047.    Copyright 2003. This article is from the April 2003 issue of the Sarasota Monitor, the official monthly publication of the Sarasota Personal Computer Users Group, Inc., P.O. Box 15889, Sarasota, FL 34277-1889. Permission to reprint is granted only to other non-profit computer user groups, provided proper credit is given to the author and our publication. We would appreciate receiving a copy of the publication the reprint appears in, please send to above address, Attn: Editor. For further information about our group, email: admin@spcug.org/ Web: http://www.spcug.org/
Number 240 - May 2003