Backup Central

I have LTO4 tapes with LTO3 barcodes on each tape. When the tapes are
checked in as scratch TSM sees the size of 1.5gb. When used they go to full
status with around 800gb on each tape. Compression is turned on. I believe
this is due to the LTO3 barcodes, since LTO3 compressed tapes are 800gb. I
need to know if this is the case that TSM is seeing these as LTO3s instead
of LTO4s. If someone could point me to some documentation I would
appreciate it. I have tried telling this to my management and they do not
believe this is so. Thank you.



Dave Hensley
Technical Analyst
McNeilus Companies, Inc.
Desk: 1-507-374-8587
Cell: 1-507-244-0921


Although this e-mail and any attachments are believed to be free of any virus or other defect which might affect any computer system, it is the responsibility of the recipient to check that it is virus-free and the sender accepts no responsibility or liability for any loss, injury, damage, cost or expense arising in any way from receipt or use thereof by the recipient.

The information contained in this electronic mail message is confidential information and intended only for the use of the individual or entity named above, and may be privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this transmission in error, please contact the sender immediately, delete this material from your computer and destroy all related paper media. Please note that the documents transmitted are not intended to be binding until a hard copy has been manually signed by all parties.
Thank you.

LTO4 are 800GB Native capacity. If you are writing compressed data on
them, that is all you are going to get.

The "compressed" capacity number that is offered is only marketing. That
is just the number you might get if your data compresses at a 2:1 ratio.
Some people's data get better or worse than that. It doesn't actually
mean anything.

From what I understand, the tape capacity only goes to Full when it
physically reaches the end of the tape.

Regards,
Shawn
________________________________________________
Shawn Drew
Data Protection Engineer
Core IT Production
BNP Paribas RCC, Inc.
Office: 201.850.6998
Mobile: 917.774.8141




Internet
dhensley < at > MCNEILUSCO.COM

Sent by: ADSM-L < at > VM.MARIST.EDU
07/17/2008 11:07 AM
Please respond to
ADSM-L < at > VM.MARIST.EDU


To
ADSM-L
cc

Subject
[ADSM-L] Tape question.





I have LTO4 tapes with LTO3 barcodes on each tape. When the tapes are
checked in as scratch TSM sees the size of 1.5gb. When used they go to
full
status with around 800gb on each tape. Compression is turned on. I believe
this is due to the LTO3 barcodes, since LTO3 compressed tapes are 800gb. I
need to know if this is the case that TSM is seeing these as LTO3s instead
of LTO4s. If someone could point me to some documentation I would
appreciate it. I have tried telling this to my management and they do not
believe this is so. Thank you.



Dave Hensley
Technical Analyst
McNeilus Companies, Inc.
Desk: 1-507-374-8587
Cell: 1-507-244-0921


Although this e-mail and any attachments are believed to be free of any
virus or other defect which might affect any computer system, it is the
responsibility of the recipient to check that it is virus-free and the
sender accepts no responsibility or liability for any loss, injury,
damage, cost or expense arising in any way from receipt or use thereof by
the recipient.

The information contained in this electronic mail message is confidential
information and intended only for the use of the individual or entity
named above, and may be privileged. If the reader of this message is not
the intended recipient, you are hereby notified that any dissemination,
distribution or copying of this communication is strictly prohibited. If
you have received this transmission in error, please contact the sender
immediately, delete this material from your computer and destroy all
related paper media. Please note that the documents transmitted are not
intended to be binding until a hard copy has been manually signed by all
parties.
Thank you.


This message and any attachments (the "message") is intended solely for
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TSM will write data until it hits the physical end of tape.
When you check a tape in, the "estimated capacity" is set by the device
class definition; you can change that to anything you want, reasonable or
not, with UPDATE DEVCLASS.
Regardless, TSM will use the full capacity of the LTO4 cartridge.

If your barcodes and/or the estimated capacity is not right, the only thing
that gets messed up is the "% utilized" of a tape in "filling" status is
less nearly correct. It's never more than a SWAG anyway, for a filling tape,
since TSM can't know ahead of time how much the next chunk of data will be
compressed by the drive.

On Thu, Jul 17, 2008 at 11:07 AM, David Hensley <dhensley < at > mcneilusco.com>
wrote:

I have LTO4 tapes with LTO3 barcodes on each tape. When the tapes are
checked in as scratch TSM sees the size of 1.5gb. When used they go to full
status with around 800gb on each tape. Compression is turned on. I believe
this is due to the LTO3 barcodes, since LTO3 compressed tapes are 800gb. I
need to know if this is the case that TSM is seeing these as LTO3s instead
of LTO4s. If someone could point me to some documentation I would
appreciate it. I have tried telling this to my management and they do not
believe this is so. Thank you.



Dave Hensley
Technical Analyst
McNeilus Companies, Inc.
Desk: 1-507-374-8587
Cell: 1-507-244-0921


Although this e-mail and any attachments are believed to be free of any
virus or other defect which might affect any computer system, it is the
responsibility of the recipient to check that it is virus-free and the
sender accepts no responsibility or liability for any loss, injury, damage,
cost or expense arising in any way from receipt or use thereof by the
recipient.

The information contained in this electronic mail message is confidential
information and intended only for the use of the individual or entity named
above, and may be privileged. If the reader of this message is not the
intended recipient, you are hereby notified that any dissemination,
distribution or copying of this communication is strictly prohibited. If
you have received this transmission in error, please contact the sender
immediately, delete this material from your computer and destroy all related
paper media. Please note that the documents transmitted are not intended to
be binding until a hard copy has been manually signed by all parties.
Thank you.

First make sure your device class has FORMAT specified as DRIVE. If the
drive is enabled for compression (check via your library's web GUI),
then you can expect anywhere from 800GB to 1.6TB of utilization. With
mixed data types I typically see ~1.2TB.

One other option to set is the ESTCAPACITY=1600G when defining/updating
the device class.

Also make sure you TSM level is 5.3.5.2 or 5.4.1 or higher.

And last but not least, $40 at CDW will get you a sheet of labels. When
tapes cost $100 each, I'm sure you can justify $2/label.

CK

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L < at > VM.MARIST.EDU] On Behalf Of
David Hensley
Sent: Thursday, July 17, 2008 10:07 AM
To: ADSM-L < at > VM.MARIST.EDU
Subject: [ADSM-L] Tape question.

I have LTO4 tapes with LTO3 barcodes on each tape. When the tapes are
checked in as scratch TSM sees the size of 1.5gb. When used they go to
full
status with around 800gb on each tape. Compression is turned on. I
believe
this is due to the LTO3 barcodes, since LTO3 compressed tapes are 800gb.
I
need to know if this is the case that TSM is seeing these as LTO3s
instead
of LTO4s. If someone could point me to some documentation I would
appreciate it. I have tried telling this to my management and they do
not
believe this is so. Thank you.



Dave Hensley
Technical Analyst
McNeilus Companies, Inc.
Desk: 1-507-374-8587
Cell: 1-507-244-0921


Although this e-mail and any attachments are believed to be free of any
virus or other defect which might affect any computer system, it is the
responsibility of the recipient to check that it is virus-free and the
sender accepts no responsibility or liability for any loss, injury,
damage, cost or expense arising in any way from receipt or use thereof
by the recipient.

The information contained in this electronic mail message is
confidential information and intended only for the use of the individual
or entity named above, and may be privileged. If the reader of this
message is not the intended recipient, you are hereby notified that any
dissemination, distribution or copying of this communication is strictly
prohibited. If you have received this transmission in error, please
contact the sender immediately, delete this material from your computer
and destroy all related paper media. Please note that the documents
transmitted are not intended to be binding until a hard copy has been
manually signed by all parties.
Thank you.