Solved

Backup Capacity

Posted on 2004-08-19
4
246 Views
Last Modified: 2010-04-03
I use Backup Exec version 9 to back up my Windows 2000 server to a DLT IV tape drive.  My question is that yesterday, I set a job to back up 110 Gig of data, and it didn't fail.  Everything I have read says that DLT IV stores 40 uncompressed/80 compressed.
The files were mostly SQL Server backup files, which I thought were pretty compressed already.

What is going on here?

Also, I get about 200 meg per min backups on average.  Does this seem normal?

Thanks!
-Jay
0
Comment
Question by:jagoodie
[X]
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
4 Comments
 
LVL 57

Expert Comment

by:Pete Long
ID: 11841063
>>Also, I get about 200 meg per min backups on average.  Does this seem normal?


thats not bad - i get about 490 \mb a minute but Ive got an MSL library running over fibre so yours is not bad at all

>>My question is that yesterday, I set a job to back up 110 Gig of data

is this a full, incremental or differential backup?
0
 
LVL 32

Accepted Solution

by:
LucF earned 100 total points
ID: 11841140
Hi jagoodie,

> The files were mostly SQL Server backup files, which I thought were pretty
> compressed already.
They can still be compressed a lot, the backups really are not heavely compressed. For a database, you can normally count on a 1:8 compression ratio.

Greetings,

LucF
0
 
LVL 22

Assisted Solution

by:dovidmichel
dovidmichel earned 25 total points
ID: 11841150
The throughput is in the normal range.

The 80gb compressed capacity is set by the marketing department and not the tech heads. Realistically the compressed capacity is more like 41gb to 100gb all depending on the type of data. Data that is already compressed such as zip, jpg, mp3... will not compress, binary types such as exe, dll, will compress very little. On the other hand plain text files will compress a lot. Also even the same data broken up into small files will compress less because each file has overhead. So lots of small files will take up more space on tape than few large files. Bottom line it depends on the data.

There is another possiblitiy but it does not come up very often, and that is if the drive is having recoverable write errors. Because they are recoverable the errors are not reported, but because there are errors blocks of tape are marked bad and so capacity is reduced. In your case this is unlikely because it also causes poor performance and at 200mb/m your performance is fine.  
0
 
LVL 2

Author Comment

by:jagoodie
ID: 11841295
Thanks for the info guys.  I just stumbled on to the Media Sets page in BE, and found that our backups are compressing at 2.8:1.  Amazing.  Plenty of free space left.
Thanks again,
Jay
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

Solid State Drive Performance Tips: Solid state storage technology is now a standard.  After testing and using several different brands and revisions of SSD's over the years I have put together a collection of tips,tools and suggestions that I ha…
This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…

734 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