Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

backing up active filesystems safely

Posted on 1998-08-04
2
Medium Priority
?
273 Views
Last Modified: 2013-11-15
I'm using Redhat Linux 5.0 with a scsi 4mm tape drive.
I don't have any problems writing to or reading from the tape.
For example:
  To backup I can type:  tar -czvSf /dev/tape /home/mag
  To restore I can type:  cat /dev/tape >foo.tar.gz
    then I can type: gzip -d foo.tar.gz
    then I can type: tar xvf foo.tar
    and I'm back in business.

I have heard that tar is not a good backup tool to use if the filesystem is changing.

Is it any part of the filesystem that corrupts the backup?  Or is it only a problem if the file being backed up changes?

Is their a failsafe method of backing up the files to a tape drive?  dump?  zip?
0
Comment
Question by:mag062397
2 Comments
 
LVL 2

Expert Comment

by:JYoungman
ID: 1637706
If the data being backed up changes during the backup,
you may find that the data on the tape for a given file does not correspond to what was the contents of the file at *any* time; it may be half-and-half or something like that.

Common wisdom has it that dump(1) is more resistant to these problems, but I haven't read the source so I'm not sure.

Personally, I do backups with tar, but duiring the night when those filesystems are not being used.

Filesystem snapshots will appear in the 2.3 or 2.5 Linux kernel series, I think, so in the end the problem will be solved the right way.

0
 
LVL 4

Accepted Solution

by:
jlms earned 140 total points
ID: 1637707
The problem of "live" filesystems is one of the filesystem you are using. Only a few recent filesystems allow you to do that, but Linux does not have them implemented (Veritas fs for example).

   So to be 100% in the safe side, you should back up filesystems that are not been used. Utilities like dump allow you to do so with the filesystem unmounted, which guarantees the fiabilty of what goes to the tape.
0

Featured Post

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

While Plesk offers many potential benefits to website administrators, including compatibility with Windows Server and other leading technologies, the company has also been working to differentiate it from other control panels for content management…
Eseutil Hard Recovery is part of exchange tool and ensures Exchange mailbox data recovery when mailbox gets corrupt due to some problem on Exchange server.
The viewer will learn how to successfully create a multiboot device using the SARDU utility on Windows 7. Start the SARDU utility: Change the image directory to wherever you store your ISOs, this will prevent you from having 2 copies of an ISO wit…
The viewer will learn how to successfully download and install the SARDU utility on Windows 8, without downloading adware.

972 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question