jsaliga
Headphoneus Supremus
- Joined
- Mar 15, 2007
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There are several types of RAID. Fault tolerant RAID is designed to protect you from a failure of a single disk. In a mirror set (RAID1), for example, data is mirrored (duplicated) from one disk to another. If the first disk fails, the second disk takes over. RAID0 is a simple stripe set with no fault tolerance. If a disk in a stripe set fails then all data on the RAID is lost.
This also means that if you accidentally delete files on your mirror set, then the deletions are also mirrored. If you find that files were accidentally deleted you cannot revert to the mirrored disk to recover them like you could with a backup, because the deleted files are also removed from the mirror. There are other types of fault tolerant RAID, but the gist is the same. None of them will protect you from accidental deletions or file corruption.
Think of it this way...a backup is preferably stored on media that is independent of the source disk they were created from. No matter what happens to the source disk, the backups are not affected. Naturally, you can create a backup of files and store it on the same disk as the source. This will protect you from accidental file deletions, but it will not protect you from a total loss of your disk or an accidental format of that disk.
For some, just having a backup on independent media doesn't go far enough. It all depends on the value of the data being protected. In my case, I have a dedicated backup server on my network, which creates backups to a 2TB disk array. When the backup to disk job completes a duplicate of that backup set is made to tape for offsite rotation. So even if my house were to burn down, I could recall my offsite tape and restore all of my data to the last backup (the prior evening). I don't think the typical home user needs to go to these lengths. My brother asked me to help him with a simple backup solution that had minimal cost but would protect his data (financial data and tax returns mostly). I set him up with an external USB 2.0 hard disk and Norton Ghost (though I don't recommend Ghost if you are running Vista x64 due to a compatibility problem.) For my brother, who is not very computer savvy, Ghost is very simple to use, can run scheduled backups, and has system tray notification on the status of your backups and the system. I am sure there are more feature-rich desktop backup solutions out there, but this one works well for my brother.
--Jerome
This also means that if you accidentally delete files on your mirror set, then the deletions are also mirrored. If you find that files were accidentally deleted you cannot revert to the mirrored disk to recover them like you could with a backup, because the deleted files are also removed from the mirror. There are other types of fault tolerant RAID, but the gist is the same. None of them will protect you from accidental deletions or file corruption.
Think of it this way...a backup is preferably stored on media that is independent of the source disk they were created from. No matter what happens to the source disk, the backups are not affected. Naturally, you can create a backup of files and store it on the same disk as the source. This will protect you from accidental file deletions, but it will not protect you from a total loss of your disk or an accidental format of that disk.
For some, just having a backup on independent media doesn't go far enough. It all depends on the value of the data being protected. In my case, I have a dedicated backup server on my network, which creates backups to a 2TB disk array. When the backup to disk job completes a duplicate of that backup set is made to tape for offsite rotation. So even if my house were to burn down, I could recall my offsite tape and restore all of my data to the last backup (the prior evening). I don't think the typical home user needs to go to these lengths. My brother asked me to help him with a simple backup solution that had minimal cost but would protect his data (financial data and tax returns mostly). I set him up with an external USB 2.0 hard disk and Norton Ghost (though I don't recommend Ghost if you are running Vista x64 due to a compatibility problem.) For my brother, who is not very computer savvy, Ghost is very simple to use, can run scheduled backups, and has system tray notification on the status of your backups and the system. I am sure there are more feature-rich desktop backup solutions out there, but this one works well for my brother.
--Jerome
