LT03 tapes not showing correct occupancy

[nikhil_1707]

Hi Team,

The tape is lto3 but still it is showing that it has 1.2 TB and other is 455.6

RAGE_POOL
KG0228L3 ORACLE_STO- LTOCLASS 455.6 G 100.0 Full
RAGE_POOL
KG0229L3 SQL_STORAG- LTOCLASS 1.2 T 44.0 Full
E_POOL

Need your advice

 

[marclant]

Physical or virtual?

 

[nikhil_1707]

This is physical tape

 

[marclant]

Can you show:

q vol KG0228L3 f=d
q vol KG0229L3 f=d

 

[nikhil_1707]

tsm: GURAPP98_SERVER1>q vol KG0228L3 f=d
Session established with server GURAPP98_SERVER1: Windows
Server Version 7, Release 1, Level 0.0
Server date/time: 01/29/2016 08:49:49 Last access: 01/29/2016 07:51


Volume Name: KG0228L3
Storage Pool Name: ORACLE_STORAGE_POOL
Device Class Name: LTOCLASS
Estimated Capacity: 455.6 G
Scaled Capacity Applied:
Pct Util: 100.0
Volume Status: Full
Access: Read/Write
Pct. Reclaimable Space: 0.0
Scratch Volume?: Yes
In Error State?: No
Number of Writable Sides: 1
Number of Times Mounted: 30
Write Pass Number: 1
Approx. Date Last Written: 03/17/2015 01:53:50
Approx. Date Last Read: 03/10/2015 01:50:46
Date Became Pending:
Number of Write Errors: 0
Number of Read Errors: 0
Volume Location:
Volume is MVS Lanfree Capable : No
Last Update by (administrator):
Last Update Date/Time: 03/10/2015 00:22:22
Begin Reclaim Period:
End Reclaim Period:
Drive Encryption Key Manager: None
Logical Block Protected: No



tsm: GURAPP98_SERVER1>q vol KG0229L3 f=d

Volume Name: KG0229L3
Storage Pool Name: SQL_STORAGE_POOL
Device Class Name: LTOCLASS
Estimated Capacity: 1.2 T
Scaled Capacity Applied:
Pct Util: 43.9
Volume Status: Full
Access: Read/Write
Pct. Reclaimable Space: 56.1
Scratch Volume?: Yes
In Error State?: No
Number of Writable Sides: 1
Number of Times Mounted: 106
Write Pass Number: 1
Approx. Date Last Written: 12/08/2015 17:07:56
Approx. Date Last Read: 12/13/2015 09:02:12
Date Became Pending:
Number of Write Errors: 0
Number of Read Errors: 0
Volume Location:
Volume is MVS Lanfree Capable : No
Last Update by (administrator):
Last Update Date/Time: 11/26/2015 13:25:08
Begin Reclaim Period:
End Reclaim Period:
Drive Encryption Key Manager: None
Logical Block Protected: No

 

[marclant]

Is the "Estimated Capacity" blank or set at 1.2TB on the device class LTOCLASS?

 

[nikhil_1707]

Hi Marclant,

It is blank.

sm: GURAPP98_SERVER1>q devc LTOCLASS f=d

Device Class Name: LTOCLASS
Device Access Strategy: Sequential
Storage Pool Count: 14
Device Type: LTO
Format: DRIVE
Est/Max Capacity (MB):
Mount Limit: DRIVES
Mount Wait (min): 10
Mount Retention (min): 10
Label Prefix: ADSM
Drive Letter:
Library: 3576LIB
Directory:
Server Name:
Retry Period:
Retry Interval:
Twosided:
Shared:
High-level Address:
Minimum Capacity:
WORM: No
Drive Encryption: Allow
Scaled Capacity:
Primary Allocation (MB):
Secondary Allocation (MB):
Compression:
Retention:
Protection:
Expiration Date:
Unit:
Logical Block Protection: No
ast Update by (administrator): ADMIN
Last Update Date/Time: 12/27/2012 18:43:00

 

[nikhil_1707]

any update

 

[erwanns]

Hello,
If you look at your filling volumes, they all have the same estimated capacity for a given device class. But if you look at your full volumes, they all have an estimated capacity based actual data written to the tape by TSM. Depending on the average compression level for the written data (from null to higher than regular 2:1), this estimated capacity can be close to native capacity or much higher. An estimated capacity of 1,2 TB for an LTO3 tape means that average data compression was 3:1.

 

[DazRaz]

There is no problem here. The drives compress data onto the tape. The amount of compression varies depending on the data. The tapes have 400G physical space and it is usual to get approx 800G on them. The tape with 1.2TB has got a good amount of compression. The tape with 455GB has data that is not very compressable.

Oops. Said much the same thing as erwanns....