Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

How data is stored on a backup tape.

Posted on 2004-09-26
3
264 Views
Last Modified: 2010-04-10
Could someone help me to understand how Data is stored on a backuptape, How is it indexed. When doing a differential backup, is the tape formatted every  time it`s being read to? Should the tape be formatted now and then to avoid problems?  Why? And please give me all informations that You think is relevant to this topic.
0
Comment
Question by:TorgN
3 Comments
 
LVL 9

Expert Comment

by:cooledit
ID: 12158058
hi, there

Backup's is stored as single files on the tapes. The indexing is done by individual program's but in theory if you do a backup from Windows Native backup or let's say Veritas then each differental program's is capable of restoring the data.

For the differental backup the tape is not erased. If you wanna reuse tape's then it's better to format it, relabel it.
0
 
LVL 2

Accepted Solution

by:
cyrax earned 250 total points
ID: 12158128
TorgN,

Data is stored on a backup tape sequentially. This means that data is written to the tape in one contiunous, long stream. It can be likened to the music on an audio tape that plays a song as the tape advances.

Indexing is used to provide a reference to all of the portions of data on the tape. If for example, a tape has a stream of data with each data portioned into five sections, labelled 1, 2, 3, 4, 5. If you wanted to access some particular data at portion '4' of the tape, the index will tell the operating system or backup/restore program where on the tape the data is located relative to the other data.

A differential backup on the other hand, looks at the current data being backed up and compares it with the records of the data on the tape. It will only back up the data that has changed.

Normally the tape will only be formatted if you specify it.

There are many resources on the Internet that explain backup methodologies. Here is one of them:
http://www.pctechguide.com/15tape.htm

Good luck!

-Cyrax-
0
 

Author Comment

by:TorgN
ID: 12158180
Thank you for the help it helped me understand the essense of Tape Backup :)
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
MAC address learning of Riverbed 4 65
Reccomended programming language for client-server applications 12 126
Current Mac OS X Network Profiles and Firewall 5 72
Vyos VLANs 14 29
Let’s list some of the technologies that enable smooth teleworking. 
PRTG Network Monitor lets you monitor your bandwidth usage, so you know who is using up your bandwidth, and what they're using it for.
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

789 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