Symptoms

Multiple alerts can indicate this pool space issue: Automatic snapshot deletion paused, because the storage pool could not reach the pool-used-space high threshold. This storage pool has exceeded the capacity threshold you specified. To allocate more storage space, add additional disks to your system. Pool space utilization has reached 95%

Cause

Accumulated snapshots and oversubscription consume significant space over time, causing high pool utilization.

Resolution

The file systems (FS), Logical Unit Numbers (LUN), and snapshots need free space in the pool in order to properly perform. This is done by expanding the impacted pool. If the impacted pool cannot be expanded, then free space must be made in the pool by one of the following methods: Delete snapshotsExpand the storage pool (using existing drives or purchasing additional drives if there are slots available)Remove unneeded resources (LUN or FS)Run the space reclaim procedure (from the host-side) to potentially free-up space which has not been zeroed-out on the array side Reclaiming VMFS deleted blocks on Thin Provisioned LUNs (external link) Investigate preallocated space concerns Dell Unity: Pool Space Issues Due To Large Levels Of Preallocated Space Additional Tips Automate snapshot deletion: Set retention policies to automatically delete old snapshots.Review snapshot schedules: Avoid overly frequent snapshot creation.Enable alerts: Configure alerts for pool usage thresholds (for example, 80%, 90%) to act proactively. Related Documents: Dell Unity™ Family Unisphere® Interface User Guide Version 5.5.1 Related Dell Knowledgebase Articles: Dell Unity: Automatic Snapshot Deletion Becomes PausedDell Unity: Storage Processor Panic During A Pool Full Event If further help is needed, contact Dell Technical Support and reference this Dell Knowledgebase Article.

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