The point was that two HBAs for tape only provides bandwidth for two tape
drives with compressible data, not four. Many people seem to under
appreciate the bandwidth requirements of a properly designed tape system.
For database data, it is usually the disk that is to slow to achieve
optimum backup speeds. Yes, you can run the tape drive at a slower speed,
but why design to do that?
Orville L. Lantto
Datatrend Technologies, Inc. (http://www.datatrend.com)
IBM Premier Business Partner
121 Cheshire Lane, Suite 700
Minnetonka, MN 55305
Email: Orville.Lantto AT datatrend DOT com
CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is
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"Loon, E.J. van - SPLXM" <Eric-van.Loon AT KLM DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
02/09/2005 02:13 AM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To
ADSM-L AT VM.MARIST DOT EDU
cc
Subject
Re: Number of HBA's
Hi Orville!
I don't think this is really necessary since LTO2. LTO1 performance does
suffer when you can't keep the drive streaming, but LTO2 and 3 adjust
their
tape speed if they detect that the amount of incoming data is too low. So
there should not be any back-hitching here...
Kindest regards,
Eric van Loon
KLM Royal Dutch Airlines
-----Original Message-----
From: Orville Lantto [mailto:orville.lantto AT DATATREND DOT COM]
Sent: Tuesday, February 08, 2005 21:33
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Number of HBA's
Don't forget drive compression when making throughput calculations! 80
MB/sec * 4 (compression of text data) =320 MB/second as the maximum
available bandwidth per LTO-3 drive.
Good Luck keeping ONE of these beasts streaming with high compression!
Orville L. Lantto
Datatrend Technologies, Inc. (http://www.datatrend.com)
IBM Premier Business Partner
121 Cheshire Lane, Suite 700
Minnetonka, MN 55305
Email: Orville.Lantto AT datatrend DOT com
CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is
for the sole use of the intended recipient(s) and may contain confidential
and privileged information. Any unauthorized review, use, disclosure or
distribution is prohibited. If you are not the intended recipient, please
contact the sender by reply e-mail and destroy all copies of the original
message.
Ben Bullock <bbullock AT MICRON DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
02/08/2005 02:10 PM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To
ADSM-L AT VM.MARIST DOT EDU
cc
Subject
Re: Number of HBA's
The documents say you are supposed to NOT have SAN and
tape
devices running on the same HBAs.
I would expect you would use 2 HBAs to connect to the SAN
and 2
to connect to the tape drives. 2 cards have more than enough bandwidth
to support the 4 LTO3 drives.
Ben
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Stef Coene
Sent: Tuesday, February 08, 2005 1:03 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Number of HBA's
Hi,
For a setup with:
- 4 x LTO3 drives in a IBM 3583 library
- 1 oracle database server: 40GB/1hr archives that needs to backuped
(AIX
LPAR) over the SAN
- 1 TSM server (AIX LPAR)
What with the HBA's? Is it needed to split the tape and disk activity
and to put 4 HBA's in the oracle DB (2 HBA's for disk activitiy and 2
for tape)?
Idem for the TSM server. 2 HBA's or 4 HBA's?
Stef
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