I want to begin a backup system that will enable me to rebuild an entire harddisk after a failure. I have a CD-RW and would like to hear your opinions on the best possible approach. Should I be looking at a complete or partial backup? Can I use my CD-RW? What applications should I be using? How will a complete restore or partial restore work?
First of all, congratulations on your decision to implement a backup strategy for your data. Disaster recovery can quickly fall to the bottom of a busy IT person's list of priorities until it's too late - you are to be commended for your foresight.
While there can be, (and have been,) volumes of material written on developing a viable backup plan, (run a search on any of the TechTarget offerings if you don't believe me,) let me offer a few tips to get you started:
- Of course you can. You can store your data backup on any media that will support the appropriate file size: CD, disk drive, tape, etc. Please be aware of those size limitations - a CD-RW, for example, will only hold 650MB of data on a single disc, which in terms of modern computers is NOT enough space to house a full system backup of OS AND all data. You have the option of spanning multiple CD-RW's to create a complete backup, using a single CD-RW and only backing up specific data, or selecting a different media type. This decision must be based on all relevant factors, including budget and time considerations. The time required to perform the backup, as well as to restore from it. In terms of which application to use, your CD-RW vendor will likely have provided its own software options for performing backups. Beyond that, the Microsoft operating systems provide a basically functional backup utility within the operating system, or you can opt for a third-party utility.
- What is a good approach in terms of complete vs. partial vs. time?: Rather than re-invent the wheel, I will quote one of the ATE team members from searchstorage.com, Jim Booth. "As a backup practice, both incremental and differential backups accomplish the same thing: They allow you to reduce the resources needed to backup data. But how they accomplish this task is different.
If archive bits are cleared after each backup, this is called an "incremental" backup. If the archive bits are cleared only after a full backup, then this is a "differential" backup.
An incremental backup clears the archive bits each time data is backed up. This means that each backup will be small. To perform a restore, a copy of the last full backup and each incremental will have to be restored to get all files to their last known state. In most cases, a full backup will be performed weekly while an incremental backup is performed daily.
A differential backup clears archive bits only after a full backup. This means that daily backups get gradually larger, but a restore is easier. A full restore only requires the last full backup and the last differential.
Incremental backup allows for a more granular restore, but differential backups are typically easier to restore."
This should give you a place to start your research in this matter. Searchstorage.techtarget.com can provide much more reference material and information, as well as a generic search engine query.
This was first published in June 2002