System Image

[ArticlesTeam]

               

Introduction:

An Image File is comprised of all the data contained on all the (written) sectors of the hard disk. Creating an Image file is the equivalent of duplicating everything on the drive, including installed programs. When it comes to backup strategy, the image file backup is the way to go. It is the most comprehensive and complete backup you can make that will insure the safekeeping and quick restoration of your operating system. Once you've familiarized yourself with the backup strategy this article details, you can develop your own strategy tailored to suit your particular situation.

After you've created your backup image, saving the archived file to a safe, secure media is tantamount to good security measures and plain common sense.

Most image creation software will offer the options to save your backup to any of several locations including Compact Digital Disk (CD), Digital Versatile Disk (DVD), Network Location(s), or Universal Serial Bus (USB) Thumb drives.

As a note of caution, one should avoid storing the backup image on the hard drive alone. Storing it there is fine as long as you also have it stored on some other removable media.

Basic Imaging Strategy:

These days, there are several good programs available on the market that are designed for Image File creation. Most of these require a purchased license version to enjoy the full functionality of the software although many of them also offer a free trial. However, we will use one of the free programs available to perform this function.

Step 1
Download and install Macrium Reflect's free edition imaging software.

Step 2
Open the software, find your drive on the list and click on it. From the menu at the top, select Backup and Create Image.

Step 3
Follow the wizard's prompts to completion.

Most of these image creating software programs will advise you to create an emergency boot disk for use in the event of a catastrophic hard disk failure. After all, what good is an image of your system if you can't even get your system to start? The programs that offer these suggestions will also walk you through the process of creating your emergency boot disk.

Advanced Imaging Strategy:

The biggest advantage to creating a Backup Image file is the easy recovery process that it affords. Should some malicious code make it's way to your hard disk, the image can restore the system in a few clicks, and a short wait for the backup file to extract. One disadvantage, if you would even consider it as a disadvantage, is that the changes to the system that took place since the time of the original backup file was made, would all be lost if you never create another backup.

So, users would find themselves in an endless cycle of creating a new backup file, then deleting the old one. This became a time consuming process for some users, as many changes can occur over time. For some, once a week and for others, more or less often. There are actually some corporate design strategies that require a backup every hour. Now, depending on the size of the disk and amount of data it contained, that could be a full time job in itself.

As it became more evident how important it is to keep current data backed up, some savvy software authors came up with the next phase to a smart backup plan...the Differential backup. As you might have guessed, this type of "Imaging Software" backup feature is designed to back up only the files that have changed since your last full back up.

Let's explain that briefly before we go on. Assume you want to back up any changes your system records. As previously stated, it varies. For some folks, that may happen every day...for others, it may be only once a week. To facilitate this example, let's assume you want to record changes every day. In an effort to keep disk space used to a minimum, you might want to use a Differential backup.

Let's go on to assume then that your last full backup was on Sunday. Your Differential backup on Monday will use up the amount of disk space required to record only the data that changed between Sunday and Monday. Next, you perform another Differential Backup on Tuesday. This backup will record only the data that changed between Sunday and Tuesday, and so on. So you see, a Differential backup compares changes to your disk between the condition it was in on the day of the original backup, and today...whatever day it happens to be.

To satisfy another demand for a more flexible Image backup of data that has changed since the last Full Backup, software authors came up with another idea...the Incremental Backup.  This, too, records only the data which has changed but it records the changes whether or not they are from the Full Backup or the Differential Backup. These type of Backup files are sometimes referred to as "cumulative incremental backups." Confused? Probably...so, let me explain further.

An Incremental Backup will record changes made since the last Incremental Backup. As with a Differential Backup, we saw how the data that is backed up is always derived from the changes that came from comparing today's backup to the original full backup. Incremental Backup files record changes derived from comparing the changes made since the last Full, Differential or Incremental Backup.

If any Backup is made on Monday, and an Incremental Backup is made on Thursday then only those data which changed between those two Backups are recorded.

What results in Incremental Backup strategy is a much smaller and faster backup. The characteristics of such backups typically are the less time between backups (although not reflected in the example above), and the less data to be recorded in the backup file.

There are some very good programs available that can perform the Differential and Incremental backups for you on a scheduled basis but these are usually from software vendors who charge a fee for the software license.

Best Practice Preparations:

If you've read this far, you're not a novice. You've also learned in your travels, that before you defrag the disk, you should always clean up first, then check the disk for errors...otherwise, you will be trying to have windows sort the errors and clutter and asking it to place THEM on the disk scattered about along with whatever free space windows also finds. Not a good idea.

Having in mind that you are about to create a Backup Image file, and if you are the type who wants to have everything perfect, or as close to it as possible then, you will see, this section was constructed just for you. You don't want to restore your operating system using an image file which contains extraneous programs/files/folders/garbage and clutter...neither would you want an image of a badly fragmented disk, or one from which there were issues caused from some disk errors. Enough said...

Let's begin by performing a disk cleanup to ensure all the clutter is gone. Click Start-->All Programs-->Accessories-->System Tools-->Disk Cleanup. Check off the following:
Downloaded Program Files, Temporary Internet Files, Recycle Bin, and Temporary Files. Click the More Options tab. Here you can remove the Windows components you KNOW that are safe for you to remove (if you are unsure about this, just skip this and go on), Installed programs that you are not using, and Old System Restore Points.

For the purpose of creating your image file, I would recommend removing all but the latest restore point to reduce the size of your operating system as much as possible in order to create the smallest image file later on. Click OK after you've made your selection(s). When the disk cleanmgr completes, the next step should be to check the disk for errors. Click start-->run...then type CMD into the run box and click OK or hit the enter key. When the command window opens, copy and paste the following into the command prompt window and press the enter key:
chkdsk /f
...the response will be a question. Please answer Yes, then reboot the computer. When your system comes up, windows will begin to check the disk and make any corrections necessary. When it completes, windows will once more automatically reboot your system.

When your system comes back up, and if you are the curious sort and want to see what corrections were made, you can view the results in your event log:

• Click start-->run...type eventvwr.msc then click OK.
  
• In Event Viewer, click the Application log.
  
• In the right pane, look down the Source column for "Winlogon" and double-click on that entry to view the results

Next, let's hunt for the presence of malicious code. Please update your on board antivirus product and perform a complete system scan of the hard disk in safe mode. Allow the software to quarantine whatever it complains of. Research those scan results to insure they are valid. Once you've determined the validity of the antivirus scan findings, please use the antivirus software to remove the items from quarantine. If your research found any of the quarantined items from the antivirus scan results to be false positives, then of course, you will want to restore those items.

Next, we need to defragment the volume. It's best to defrag in in safe mode where only a few necessary windows processes are running.

Click start-->All Programs-->Accessories-->System Tools-->Disk Defragmenter. Click on the drive that you intend to use for making your image file. If you have only one drive, the defrag utility should have opened to it directly by default and your only drive would already be highlighted. Click the Defragment button and do nothing else while the defrag process is underway. When it completes, reboot to your normal windows user mode.

Now that you've got a clean, lean machine and frothing at the bit, you think you're ready to go. Not so fast...If your first consideration is, "how many disks will I need" then you might be delightfully surprised with the results from having followed through with the remainder of these suggestions.

In order to use the least number of disks on which to store your Image File, the best plan would be to reduce the drive (now that it's clean) to it's smallest possible size. Compressing the drive before we make the image file is a good way to do that.

Right click on the drive you want to create an image of and select Properties. At the bottom of the Properties Box window, check the box Compress drive to save disk space. Click Apply and allow the time for windows to finish compressing the files that it will. It's important to note that there are some files/folders that windows will not compress.

If you are savvy enough, you could certainly peruse the drive and find those items and compress them...but, please don't do that. As stated above, just let windows compress "what it will". Those few files/folders that are not compressed automatically should be left as they are. Windows chose not to compress them for a reason so leave them be...When it completes, you are ready to begin creating the pristine Image File you wanted. Now, just follow steps 1 through 3 detailed under the Basic Imaging Strategy above. Good Luck!