Storage Foundation Thin provisioning Array Support

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Article ID: 100002482

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Updated On:

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Introduction


Storage Foundation 5.0 MP3 and later supports SmartMove to all thin provisioning capable storage and Thin Reclamation to storage hardware that supports the SF Thin Reclamation Host-Storage interface.

With the proper hardware specific Array Support Library (ASL), Storage Foundation automatically discovers luns that are thin and luns that are thinrclm. In the event that the ASL for a given storage array does not discover these device attributes, they can be set manually by a system administrator, thereby allowing the devices to be used for SmartMove and Thin Reclamation.

SmartMove is the ability to migrate from thick to thin online and automatically reclaim the unused space in the VxFS file system originally supported by the thick devices.  SmartMove can also be used to keep thin storage thin when it is used by host based mirrors.  By default, SmartMove is used for all volumes that contain one or more thin or thinrclm device.

Thin Reclamation is the ability to reclaim unused space on thinrclm devices online, without modifying host, SAN or storage array configurations.


 

The VxVM (Veritas Volume Manager) "vxdisk -o thin list" command is used to display per lun specific information for TP (Thin Provisioned) luns.
 


At time of writing, the following ASLs are capable of detecting thin provisioned LUNs and reclamation support where stated:

 

Refer to the listed HCL documents for additional content.

 
ASL and APM responsibilities:
 

 
The Array Support Library (ASL) is responsible for:
 
- Discovering the TP disks in the vendor specific method
 
- Discovering the TP attributes in the vendor specific method
 

 
The Array Policy Module (APM) is responsible for:
 
- Intelligence in how to perform reclaim in the array specific method
 
- Ensure the no space error can be handled in the array
 

Additional information on how to use these features can be found in the following documents:
 
For 5.0MP3 - Veritas Volume Manager Administrators Guide

For 5.1SP1 - Veritas Storage Foundation Advanced Features Administrators Guide

EMC DMX Array 
 
Note: Currently we do not support thin reclamation with EMC DMX arrays, as the product can only determine if a LUN is "thin" or not with regards to EMC DMX presented devices, hence no reclamation capability.
 

 
Known Issues
 
Due to known product defects surrounding Thin Provisioning, Veritas would recommend customers to deploy either 5.0 MP3 RP4 or 5.1 SP1 (or higher) for Solaris, AIX and Linux where possible.
  
Note: Solaris 8 support withdrawn for Storage Foundation 5.1.
 

Issue/Introduction

Storage Foundation Thin provisioning Array Support
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