Backup Strategies
Posted: 08 Nov 2015, 16:55
As some of my recent posts to this forum have suggested, I've lately become intimately aware of the importance of backing up one's computer files. Being an old hacker (the good kind) from way back, I figured that I had it all down pat. Well, I do, sort of. But I have changed my ways in view of my recent needs to restore my default operating system multiple times.
The question of what to back up is based on individual needs. The entire hard disk(s) with your operating system can be preserved, bit for bit, if you make a system image. This is a major task that consumes a lot of copy time and a lot of disk space depending on how large your collection of software is. But, unless you are running a business and it's critical that you recover as quickly as possible, system images are overkill. They are nice to have, but not needed by the average computer user. The better approach to backups is to list all the individual directories and files you cannot replace by simply reinstalling software and only back up those on the list. These partial backups is what most of us home computer types can live with comfortably.
Once you have a list of what you need to back up, then just do it. Copy everything on your list in it's entirety to your backup media. You can do this manually, or you can use one of many programs out there designed for just this purpose. No matter how you do it, the first backup should be complete, or a Full Backup. Thereafter the choices are more varied. Differential and Incremental backups can be made after you have a Full Backup in place.
Differential backups work off that list of all the files you want to preserve. The idea behind this techniques is to only back up the files from your master list that have changed since the last time you made a full back up. This saves copying time given that not everything has changed and only a portion of the files on your list need to be sent to the backup volume. However, as you might imagine, it takes a lot of time to hunt through all the directories manually. Differential backups are definitely a job for software that can do it automatically.
Incremental backups work off that same master list, but in this case only files that have changed since the last incremental backup are copied to the backup volume. This type of backup uses even less time to copy changes, but is equally laborious hunting down those changes manually. Software is best suited for this task as well.
Backing up systems is one thing, but recovering lost data is quite something else. It is during recovery that you discover how valuable are those backups you've made. And, the ease of recovery is totally dependent upon what kind of backups you made. Ease and speed of recovery are also largely dependent on the software you use to do it all. Needless to say the more automated the process, the better. There are a lot of options, and a good disaster recovery strategy is often overlooked until you need to use it. Then it might be too late. So, plan ahead.
RECOVERY FROM DISK IMAGE is fairly simple given that the whole ball of wax is simply copied from the backup volume to the working volume. Reboot and you are in business instantly. However, as is the case with all backups, anything new that was added since the last backup is lost. If your ability to use your computer is critical, such as in running a business, then it is worth the effort to make a disk image daily. It takes a lot of time and should be done when the system isn't being used so that nothing is missed. The good news is, disaster recovery is a snap.
RECOVERY USING FULL BACKUPS is the next best thing to restoring from an image. This process involves manually installing the original operating system and any necessary programs/drivers first. Once all the software is in place, then the list of Full Backup files is copied over to the newly installed operating system. Installing all that previously existing software could be a long time consuming process, and the success of it depends on your ability to remember exactly what you had installed before you lost it all. Thus, all that time you saved not making images is now being used to recover from disaster by clean installing software and using Full Backups.
RECOVERY USING DIFFERENTIAL BACKUPS involves one more step added on to the Full Backup recovery routine. Anything that changed since the most recent Full Backup is in the Differential Backup store. Thus those changed files must be added back in after the Full Backup was performed so that the maximum number of lost files can be recovered. This typically involves restoration of the Full and only the latest Differential Backups
RECOVERY USING INCREMENTAL BACKUPS means you must perform the Full Backup recovery routine and then all the incremental backups in the correct order. Unlike differential, the incremental backups only backup those files that have changed since the last increment. Depending on your configuration, there may be several incremental backups in storage which will require several runs of the recovery software to get back to where you were before the loss. Any time you saved by doing only incremental backups is thus used up (and then some) in the recovery process. This might not be as bad as it sounds if you don't need to recover as quickly as possible.
My strategy for my home computer has been to do incremental backups. I would make one image periodically, and then one Full Backup. Incremental Backups were made five times before I would make another Full Backup and start the cycle over again. Thus my recovery plan was to reinstall all the software I lost, then recover the Full Backup, then recover each Increment separately in the correct order. This only took three days for me but I did it all manually. My instincts would not allow me to let the software recover automatically for me. I wanted to have full control over what was being restored.
And this brings me to the choice of software I use to make backups. Most backup software will copy your files, compress them, and then arrange them in some proprietary order on your remote storage volume. This is fine if you are not paranoid and trust the software. The software I use simply copies the raw data without compressing it or arranging it in some esoteric order. The advantage is that I can go look into those back up files and pick out only what I want. I don't have to do a full restore unless I choose to. The price I pay is the time and effort to do all this manually. As I said, three days was nothing to me, but it might put you out of business if your livelihood depends on how quick you can get back what you lost.
Just for the record, I now do images and Full Backups only.
The question of what to back up is based on individual needs. The entire hard disk(s) with your operating system can be preserved, bit for bit, if you make a system image. This is a major task that consumes a lot of copy time and a lot of disk space depending on how large your collection of software is. But, unless you are running a business and it's critical that you recover as quickly as possible, system images are overkill. They are nice to have, but not needed by the average computer user. The better approach to backups is to list all the individual directories and files you cannot replace by simply reinstalling software and only back up those on the list. These partial backups is what most of us home computer types can live with comfortably.
Once you have a list of what you need to back up, then just do it. Copy everything on your list in it's entirety to your backup media. You can do this manually, or you can use one of many programs out there designed for just this purpose. No matter how you do it, the first backup should be complete, or a Full Backup. Thereafter the choices are more varied. Differential and Incremental backups can be made after you have a Full Backup in place.
Differential backups work off that list of all the files you want to preserve. The idea behind this techniques is to only back up the files from your master list that have changed since the last time you made a full back up. This saves copying time given that not everything has changed and only a portion of the files on your list need to be sent to the backup volume. However, as you might imagine, it takes a lot of time to hunt through all the directories manually. Differential backups are definitely a job for software that can do it automatically.
Incremental backups work off that same master list, but in this case only files that have changed since the last incremental backup are copied to the backup volume. This type of backup uses even less time to copy changes, but is equally laborious hunting down those changes manually. Software is best suited for this task as well.
Backing up systems is one thing, but recovering lost data is quite something else. It is during recovery that you discover how valuable are those backups you've made. And, the ease of recovery is totally dependent upon what kind of backups you made. Ease and speed of recovery are also largely dependent on the software you use to do it all. Needless to say the more automated the process, the better. There are a lot of options, and a good disaster recovery strategy is often overlooked until you need to use it. Then it might be too late. So, plan ahead.
RECOVERY FROM DISK IMAGE is fairly simple given that the whole ball of wax is simply copied from the backup volume to the working volume. Reboot and you are in business instantly. However, as is the case with all backups, anything new that was added since the last backup is lost. If your ability to use your computer is critical, such as in running a business, then it is worth the effort to make a disk image daily. It takes a lot of time and should be done when the system isn't being used so that nothing is missed. The good news is, disaster recovery is a snap.
RECOVERY USING FULL BACKUPS is the next best thing to restoring from an image. This process involves manually installing the original operating system and any necessary programs/drivers first. Once all the software is in place, then the list of Full Backup files is copied over to the newly installed operating system. Installing all that previously existing software could be a long time consuming process, and the success of it depends on your ability to remember exactly what you had installed before you lost it all. Thus, all that time you saved not making images is now being used to recover from disaster by clean installing software and using Full Backups.
RECOVERY USING DIFFERENTIAL BACKUPS involves one more step added on to the Full Backup recovery routine. Anything that changed since the most recent Full Backup is in the Differential Backup store. Thus those changed files must be added back in after the Full Backup was performed so that the maximum number of lost files can be recovered. This typically involves restoration of the Full and only the latest Differential Backups
RECOVERY USING INCREMENTAL BACKUPS means you must perform the Full Backup recovery routine and then all the incremental backups in the correct order. Unlike differential, the incremental backups only backup those files that have changed since the last increment. Depending on your configuration, there may be several incremental backups in storage which will require several runs of the recovery software to get back to where you were before the loss. Any time you saved by doing only incremental backups is thus used up (and then some) in the recovery process. This might not be as bad as it sounds if you don't need to recover as quickly as possible.
My strategy for my home computer has been to do incremental backups. I would make one image periodically, and then one Full Backup. Incremental Backups were made five times before I would make another Full Backup and start the cycle over again. Thus my recovery plan was to reinstall all the software I lost, then recover the Full Backup, then recover each Increment separately in the correct order. This only took three days for me but I did it all manually. My instincts would not allow me to let the software recover automatically for me. I wanted to have full control over what was being restored.
And this brings me to the choice of software I use to make backups. Most backup software will copy your files, compress them, and then arrange them in some proprietary order on your remote storage volume. This is fine if you are not paranoid and trust the software. The software I use simply copies the raw data without compressing it or arranging it in some esoteric order. The advantage is that I can go look into those back up files and pick out only what I want. I don't have to do a full restore unless I choose to. The price I pay is the time and effort to do all this manually. As I said, three days was nothing to me, but it might put you out of business if your livelihood depends on how quick you can get back what you lost.
Just for the record, I now do images and Full Backups only.