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====== TSM dedup on server side ======

TSM deduplication ratios typically range from 2:1 (50% reduction) to 15:1 (93% reduction)

snappdiff incremental is supported on container
snappmirror is **not** supported on container
TOC is **not** supported on container

===== Get dedup stats on a specific node =====

The generate process can be very long to run
<cli prompt='>'>
Protect: ISPTST> GENERATE DEDUPSTATS CONTAINER1 NODE1
Protect: ISPTEST1>QUERY DEDUPSTATS

Date/Time               Storage        Node Name      Filespace      FSID     Type     Total Saving        Total Data (MB)               Pool Name                     Name                             Percentage       Protected 
-------------------     ----------     ----------     ----------     ----     ----     ------------     ---------
02/12/2021 12:03:47     CONTAINER1     NODE1          /var/log/audit   10     Bkup            26.39            13
</cli>

You can also run this command by adding a filespace name to reduce processing time


===== Change deduplication file size limit =====

Files bigger than 300GB won't be deduplicated, by default on client side. Use the CLIENTDEDUPTXNlimit server option to specify the maximum size for a transaction (range between 32 – 2048 GB, default 300 GB).
  setopt CLIENTDEDUPTXNlimit 80

Disable server-side deduplication for all objects over 1024 GB (range between 32-2048GB, default 300 GB):
  setopt SERVERDEDUPTXNlimit 1024

SPLITLARGEOBJECTS setting. This is introduced in v7.1 and is part of the increased data deduplication and scalability, allowing v7.1 for up to 10 times more ingest rate compared with previous TSM versions.

SPLITLARGEOBJECTS will split (segment) a file that is bigger then 10 GB into smaller pieces (fragments).

SPLITLARGEObjects=Yes or NO. YES is the default. Available as a parameter of the following commands:
  register node
  update node

Note: if you want to maximize the throught of backups that are going directly to tape, disable SPLITLARGEObjects:
  update node xxxx SPLITLARGEObjects=no
  
===== Deduplication ratio and percent calculation =====

<cli prompt='>'>
TSM> select stgpool_name,est_capacity_mb,pct_utilized,space_saved_mb from stgpools
</cli>

data physically stored in stgpool: 
  est_capacity_mb x pct_utilized / 100

total data backed up: 
  space_saved_mb + (est_capacity_mb x pct_utilized / 100)

data not stored, duplicate shrunk: 
  space_saved_mb

**to calaculate the percentage of data not stored:**
  100 x space_saved_mb / (space_saved_mb + (est_capacity_mb x pct_utilized / 100))
  
**to calaculate the ratio of data not stored <value>:1**
  value= (space_saved_mb / (est_capacity_mb x pct_utilized / 100))

===== Dedup technology =====

^ ^ ^Server side NextGen dedupe in container stgpool^Server side legacy dedupe in file dev stgpool^Client side dedupe with container stgpool^Client side dedupe with legacy file dev stgpool^
| |When is data deduped|Server side Inline|Out-of-Band: Dedupe processing & reclamation required after backups finish|Before client sends data to server|Before client sends data to server|
| |Data transferred from client  to server|Fully hydrated data|Fully hydrated data|Dehydrated data	|Dehydrated data|
| |Where is data stored|Container Stgpool|File Dev Class Stgpool|Container Stgpool|File Dev Class Stgpool|
| |Storage pool encryption supported|	Yes in cloud containers	|No|Yes in cloud containers|No|
| |Compression|Yes (7.1.5)|No (client side only)|Yes (not recommended)|Yes (not recommended)|
| |Client side encryption supported|Yes (not deduped)|Yes (not deduped)|No (SSL works with dedupe)|No (SSL works with dedupe)|
| |“protect stgpool”|Yes in directory containers|No|Yes in directory containers|No|
| |(Replicate data only)| | | | |
| |“repair stgpool”|Yes in directory containers|No|Yes in directory containers|No|
| |“replicate node”|Yes|Yes|Yes|Yes|
| |(Replicate data & meta data)| | | | |
| |“replicate node recoverdamaged=yes”|No|Yes|No|Yes|
| |Stgpool reclamation required	|No|Yes|No|Yes|
| |TSM version supported|7.1.3+|6.1+|7.1.3+|6.2+|
| |Special license needed|No|No|No|No|
| |Amount of data processed per day|80 TB per day|20 TB per day|100 TB per day|30 TB per day|
| |Data managed on a single TSM server|1 to 4 PB|100 to 400 TB|1 to 4 PB|100 to 400 TB|
| |Max physical capacity on a TSM server|1 PB|100TB|1 PB|100TB|
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