ESTIMATED CAPACITY OF LTO4's

[cozcol]

Hi all,

My ESTIMATED CAPACITY OF LTO4's should be 1.6TB, however some are allocated this but others are alocated only half this 850GB.

Please see my q drive f=d , q vol , q libvol , q=devclass f=d below

tsm: TSM_PROD01>q drive f=d
Session established with server TSM_PROD01: Linux/x86_64
Server Version 5, Release 5, Level 1.0
Server date/time: 01/22/2009 16:06:48 Last access: 01/22/2009 15:44:52
 
Library Name: TS3100
Drive Name: DRIVE1
Device Type: LTO
On-Line: Yes
Read Formats: ULTRIUM4C,ULTRIUM4,ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2
Write Formats: ULTRIUM4C,ULTRIUM4,ULTRIUM3C,ULTRIUM3
Element: 256
Drive State: UNKNOWN
Volume Name: 007ABWL4
Allocated to:
WWN: 5000E11118EF7001
Serial Number: 1K10002387
Last Update by (administrator): ADMIN
Last Update Date/Time: 09/18/2008 17:03:46
Cleaning Frequency (Gigabytes/ASNEEDED/NONE): ASNEEDED
Library Name: TS3100
Drive Name: DRIVE2
Device Type: LTO
On-Line: Yes
Read Formats: ULTRIUM4C,ULTRIUM4,ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2
Write Formats: ULTRIUM4C,ULTRIUM4,ULTRIUM3C,ULTRIUM3
Element: 257
Drive State: LOADED
Volume Name: 011ABWL4
Allocated to:
WWN: 5000E11118EF7004
Serial Number: 1K10002592
Last Update by (administrator): ADMIN
Last Update Date/Time: 09/29/2008 15:58:40
Cleaning Frequency (Gigabytes/ASNEEDED/NONE): ASNEEDED
 
tsm: TSM_PROD01>q vol 008* f=d
Volume Name: 008ABWL4
Storage Pool Name: OFFSITE
Device Class Name: TS3100
Estimated Capacity: 828.9 G
Scaled Capacity Applied:
Pct Util: 40.1
Volume Status: Full
Access: Unavailable
Pct. Reclaimable Space: 59.9
Scratch Volume?: Yes
In Error State?: No
Number of Writable Sides: 1
Number of Times Mounted: 6
Write Pass Number: 1
Approx. Date Last Written: 10/21/2008 08:54:42
Approx. Date Last Read: 10/13/2008 11:04:29
Date Became Pending:
Number of Write Errors: 0
Number of Read Errors: 0
Volume Location: LTOPOOL01
Volume is MVS Lanfree Capable : No
Last Update by (administrator): ADMIN
Last Update Date/Time: 01/22/2009 15:21:55
Begin Reclaim Period:
End Reclaim Period:
Drive Encryption Key Manager: None
 
 
 
 
tsm: TSM_PROD01>q libv
Library Name Volume Name Status Owner Last Use Home Device
Element Type
------------ ----------- ---------------- ---------- --------- ------- ------
TS3100 005ABWL4 Private Data 4,100
TS3100 007ABWL4 Private Data 4,110
TS3100 010ABWL4 Private Data 4,099
TS3100 011ABWL4 Private Data 4,101
TS3100 012ABWL4 Scratch 4,103
TS3100 090ABWL4 Private Data 4,117
TS3100 092ABWL4 Private Data 4,113
TS3100 093ABWL4 Private Data 4,107
TS3100 094ABWL4 Private Data 4,109
TS3100 100ABWL4 Private Data 4,098
TS3100 101ABWL4 Private Data 4,108
TS3100 102ABWL4 Private Data 4,111
tsm: TSM_PROD01>q vol
Volume Name Storage Device Estimated Pct Volume
Pool Name Class Name Capacity Util Status
------------------------ ----------- ---------- --------- ----- --------
*ABWL4 OFFSITE TS3100 0.0 M 0.0 Empty
/opt/tivoli/tsm/stg01/0- FILE_STG01 FILEDEVC 2.0 G 100.0 Full
0001404.BFS
/opt/tivoli/tsm/stg01/0- FILE_STG01 FILEDEVC 2.0 G 100.0 Full
0001405.BFS
/opt/tivoli/tsm/stg01/0- FILE_STG01 FILEDEVC 2.0 G 60.8 Filling
0001406.BFS
005ABWL4 LTOPOOL01 TS3100 850.6 G          0.3 Full
006ABWL4 LTOPOOL01 TS3100 819.7 G         91.6 Full
007ABWL4 LTOPOOL01 TS3100 1.6 T            37.2 Filling
008ABWL4 OFFSITE     TS3100 828.9 G         40.1 Full
009ABWL4 OFFSITE     TS3100 1.6 T            35.0 Filling
010ABWL4 OFFSITE     TS3100 1.6 T            24.9 Filling
090ABWL4 OFFSITE     TS3100 820.8 G         97.5 Full
091ABWL4 LTOPOOL01 TS3100 828.6 G         32.2 Full
092ABWL4 LTOPOOL01 TS3100 822.6 G         100.0 Full
093ABWL4 LTOPOOL01 TS3100 824.3 G         88.9 Full
094ABWL4 LTOPOOL01 TS3100 818.1 G         95.1 Full
100ABWL4 LTOPOOL01 TS3100 819.0 G         100.0 Full
101ABWL4 LTOPOOL01 TS3100 421.1 G         100.0 Full
102ABWL4 OFFSITE     TS3100 412.3 G         99.5 Full
 
tsm: TSM_PROD01>"select volume_name, pct_reclaim, stgpool_name from volumes where pct_reclaim >=90 order by 3,2 asc"
Session established with server TSM_PROD01: Linux/x86_64
Server Version 5, Release 5, Level 1.0
Server date/time: 01/22/2009 16:27:07 Last access: 01/22/2009 16:06:48
ANR2000E Unknown command - select volume_name, pct_reclaim.
ANS8001I Return code 3.
tsm: TSM_PROD01>select volume_name, pct_reclaim, stgpool_name from volumes where pct_reclaim >=90 order by 3,2 a sc
VOLUME_NAME PCT_RECLAIM STGPOOL_NAME
------------------ ----------- ------------------
005ABWL4 99.6 LTOPOOL01

 

[LukeLu]

You can use the following command to update estimated capacity:
update devclass LTO4 estcapacity=1600G

 

[Leigh]

doing a 'q vol' we're seeing a max of 3.6TB per Gen4 tape.

 

[LukeLu]

As mikeymac said in his posting. The amount of data depends on the type of data and compression ratio. www.lto4.org has the number 800GB/1600GB native/compressed.

 

[schetan]

And it depends a lot on the type of data stored on those tapes.
We're not using LTO4 yet but even at LTO3 level (rated 400GB/800GB compressed) we're getting actual capacities across the entire map.

For example. On tapes that store our VM backups (a format that's already precompressed) we're only getting about 400-420GB/tape, whereas our DB2 backups fit over 1.2TB per volume which is way over the 800GB rating.

So for sure, check if you have compression enabled on the drives, if you do and you're still getting low capacities, look at the type of data you're storing.
But there's not much you can do about that.

 

[heada]

You should never compress twice or more as you will normally get a slightly larger file than what you started with. Ideally, you want to have compression on at the hardware level as that will be the lowest overhead method. If not at the hardware level, the next best place to have it is at the client before the data is transmitted to the server. In these cases, with hardware compression, you should see the higher usage of tapes, in the 1600GB range depending on how compressible the data is. Databases compress very well whereas binaries do not. If you have compression enabled on the clients, you should see near the native capacity of the tapes or about 800GB.

-Aaron

 

[cozcol]

Thanks ALL for your suggestions and help. I believe I have compression enabled on the Drives. But will double check this. But I thought the option on the drive ULTRIUM4C wasthe compression option?


Like you have mentioned it may be the type of data being backed up.

I have added the 1600MB estimated capacity to the Devclass but this defintely hasn't cvhanged the tapes which are already in the pool and have been written to.

I have seen this mentioned in previous threads so it works as expected.

So will have to keep a check on new volumes going into the pool.

Once again thanks for your responses.

Great Place to be here and exceptional help and support from ADSM.ORG .

Cozcol

 

[BBB]

Cozcol just to clarify what you are seeing:

The estimated capacity is something you can change and will be inherited by any new tapes at the time they are added to the storage pool / go into the filling state. Existing filling/full tape volumes will not be changed if you update the device class's estcap value.

At the moment the tape becomes full, the individual tape's estimated capacity is changed to how much data was eventually fit onto the tape, so its no longer an estimate at that point. This value will then stay constant for that tape volume until the tape is reclaimed and the process starts all over again.

 

[cozcol]

Thanks for the clarification BBB and as ever you're a great help.