backups...

jok.mc.haggis

does a differential reset the archive bit.
does system show that it has been backed up after a differential back up?

hhisgett

Check this thread out. This topic was discussed very good recently.


http://www.techexams.net/forums/viewtopic.php?t=6029

janmike

Differential does not reset the archive bit. Differential will backup everthing changed since the last full backup--generally it's set up that way anyhow. So, if you keep backing up everyday on differential and not do another incremental or full backup, which do reset the archive bit, the diff. backup will take an unreasonably long time.

You can set up logs/reports that will tell you when a backup has been done. Or you can just tell when the tape drive stops. Most tape drives have indicator lights or small readout screens that will let you know these things.

If you've never worked in that kind of environment, it's kind of hard to visualize the process. But, A+ shouldn't be too hard on you. Just know what the basic kinds of backups do and what they're used for. Generally a systems administrator restores the backups, not an A+ tech.

jok.mc.haggis

right thanks for replies....
i think it was question 27 or something on the OS practice test on this site basically asked which backup could be used to back up everything so that it would appear as though no backup was made... i said differential...
according to the answer and explanation provided, the copy back up was the only one that would appear as though no back up were made?

janmike

Indeed, that's true! A copy is just a copy. But, it can be saved and considered a backup. That's what we do with software, and we're allowed to do that--make a copy to use and keep the original tucked away in a safe place.

But somewhere in the logs inside the computer, there is a difference made but I don't think either one has any effect on the amount of material that is backed up. If you make a copy of a file one day and save it away, and you make a differential backup of that same file and save it away, you have a source of redundant data with which you can recreate that file. Then if the file disappears from the computer hard drive, you can "replace" the original file by copying a new file from the copy using operating system commands. Or, you can "restore" the file from the differential backup you make using backup software. It's a choice of methods, but the differential backup knows its a backup and not a copy. There will be information on the tape that will tell backup programs that it's a backup. And, I guess the difference is, I don't believe that you would use a copy to restore a file using backup software and you can't just copy a file from a backup tape and paste it onto a hard drive.

I believe, anyway, that this is in general the way things go. But I might be missing something.

Hope this explains the difference.