Dell EMC Unity:Customer is reporting high pool oversubscription (User Correctable)

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Instructions

Customer is having 219% pool subscription however pool is still having  nearly 50 % free capacity on the mentioned pool as per below:
 
kA5f1000000CdwCCAS_1_0
On analysing the FS on the pool, it was found that there is a 5 TB FS with 18 snaps as per below:
kA5f1000000CdwCCAS_1_1
 
Each snap subscription equal to the FS/LUN size. If file system/lun size is 5 TB, each snap for this fs/lun subscription will be 5 TB. This is because in worse case scenario each snap potentially might need the same amount of space as the production file system/lun. For example, if you have a 5 TB file system and you fill it up completely, then take a snap, then delete everything from the file system, and fill it up again with different data - in this scenario the snap will consume 5TB and the FS will consume 5 TB. Snap subscription takes into account the worse case scenario.

Please note that how oversubscription is calculated is mentioned clearly on this KB: https://support.emc.com/kb/491974

Affected Products

Dell EMC Unity Family

Products

Dell Unity 300, Dell EMC Unity 300F, Dell EMC Unity 350F, Dell EMC Unity 400, Dell EMC Unity 450F, Dell EMC Unity 500, Dell EMC Unity 500F, Dell EMC Unity 550F, Dell EMC Unity 600, Dell EMC Unity 600F, Dell EMC Unity 650F , Dell EMC Unity Family |Dell EMC Unity All Flash, Dell EMC Unity Family ...
Article Properties
Article Number: 000022447
Article Type: How To
Last Modified: 16 Oct 2025
Version:  3
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.