Clifford:
After talking with my client over the weekend and
finding out what they were backing up, I found that
they were some db files. These files had a lot
of 'white space' or otherwise called sparse files that
when backed up will compress much more than the
advertised drive spec.
David
Quoting Dustin Scharf <dusty AT veritas DOT com>:
> 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
> _______________________________________________
> Veritas-bu maillist - Veritas-
bu AT mailman.eng.auburn DOT edu
>
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-
bu
>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
David A. Chapa
Consulting Manager
DataStaff, Inc.
847 413 1144
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