Veritas-bu

[Veritas-bu] RE: [NBUADV-L]: compression and DLT 7000

2001-02-16 17:37:30
Subject: [Veritas-bu] RE: [NBUADV-L]: compression and DLT 7000
From: Dustin Scharf dusty AT veritas DOT com
Date: Fri, 16 Feb 2001 17:37:30 -0500
Absolutely.  For example, at a previous job we rutinely (sp?) got 15:1
compression from a an application using a cobol database... tons of white
(blank) space in the files.  we would get well over 300GB of data on a
single DLT tape.  Conversely, try backing up a bunch of zip files or already
compressed files... you won't get near the 70GB.

Dustin

Dustin Scharf
Veritas Education Services
dusty AT veritas DOT com


-----Original Message-----
From: Stephen Dvorak [mailto:sdvorak AT veritas DOT com]
Sent: Friday, February 16, 2001 3:40 PM
To: 'David A. Chapa'; clifford thurber;
veritas-bu AT mailman.eng.auburn DOT edu
Cc: nbu-lserv AT datastaff DOT com
Subject: RE: [NBUADV-L]: compression and DLT 7000


The 70GB limit on DLT 7000 drives is assuming 2:1 compression.  The drive is
capable of producing greater compression rates than this.  Thus, if the data
is highly compressable, the drive should be able to get better than 2:1.
Steve

-----Original Message-----
From: David A. Chapa [mailto:david AT datastaff DOT com]
Sent: Friday, February 16, 2001 2:33 PM
To: clifford thurber; veritas-bu AT mailman.eng.auburn DOT edu
Cc: nbu-lserv AT datastaff DOT com
Subject: RE: [NBUADV-L]: compression and DLT 7000


I've seen the same thing at another customer's site...the Veritas SE that
was onsite before me said that it may be due to some HIGHLY compressable
data...I'm not sure I know what that means since I haven't had an
opportunity to research it further.

David

<><><><><><><><><><><><><><><><><><><><>
David A. Chapa
Consulting Manager
DataStaff, Inc.
847 413 1144
http://www.consulting.datastaff.com
---------------------------------------
NBU-LSERV AT datastaff DOT com - Adv. Scripting

-----Original Message-----
From: owner-nbu-lserv AT datastaff DOT com
[mailto:owner-nbu-lserv AT datastaff DOT com]On Behalf Of clifford thurber
Sent: Friday, February 16, 2001 2:05 PM
To: veritas-bu AT mailman.eng.auburn DOT edu
Cc: nbu-lserv AT datastaff DOT com
Subject: [NBUADV-L]: compression and DLT 7000


Hello,
We are using Netbackup 3.2 on Solaris 7 with Quantam DLT 7000 Drives. We
have the following line in our st.conf file
DLT7k-data =    1,0x36,0,0x9639,4,0x84,0x83,0x0,0x85,3;
Which I believe denotes that we have 70GB of storage in  compressed mode. I
also believe that this is the theoretical limiton DLT 7000's using
compression. The confusing part is that when I run the media list report I
see tapes that are 87GB, 129GB and 111GB. Can someone tell me how this is
even possible? Veritas was not able to give me an answer to this? Thanks in
advance I will summarize.
Clifford

-------------------------------------------------------
NBU-LSERV AT datastaff DOT com - Advanced NetBackup Scripting
http://www.consulting.datastaff.com/adv_script_site


-------------------------------------------------------
NBU-LSERV AT datastaff DOT com - Advanced NetBackup Scripting
http://www.consulting.datastaff.com/adv_script_site
-------------------------------------------------------
NBU-LSERV AT datastaff DOT com - Advanced NetBackup Scripting
http://www.consulting.datastaff.com/adv_script_site



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