> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt # Fix Storage Issues `Disk Space % Used` alerts indicate the percentage of used disk space on a partition reaches a specified threshold. **Note:** This alert doesn't apply to Atlas Infinite clusters, where Atlas manages storage independently of the compute nodes. For Atlas Infinite clusters, Atlas instead raises the [`Atlas Infinite: Storage Space Used % is`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-Atlas-Infinite--Storage-Space-Used---is) alert when the cluster's [logical data size](https://www.mongodb.com/docs/atlas/infinite/atlas-infinite-storage.md#std-label-atlas-logical-data-size) approaches its [max storage limit.](https://www.mongodb.com/docs/atlas/infinite/atlas-infinite-storage.md#std-label-atlas-infinite-max-storage-limit) **Note:** The UI displays GB, but all disk space metrics are in gibibytes (GiB). ## Alert Conditions Configured by Default Atlas configures the following alert conditions by default to help you ensure dedicated cluster availability and prevent the cluster from going down due to disk exhaustion on the primary node and to maintain read availability. **Note:** If the [`Project Owner`](https://www.mongodb.com/docs/atlas/reference/user-roles.md#mongodb-authrole-Project-Owner) role is assigned to a human project member, Atlas delivers alerts to that member's configured email address or SMS target. If the [`Project Owner`](https://www.mongodb.com/docs/atlas/reference/user-roles.md#mongodb-authrole-Project-Owner) role is assigned programmatically, ensure you configure an explicit notification target (such as an email address, PagerDuty, Slack, or Webhook) to receive alerts. Programmatic API keys and service accounts do not receive alert notifications by default. - [`Writes have been blocked on your cluster due to critically low available storage`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-Writes-have-been-blocked-on-your-cluster-due-to-critically-low-available-storage) occurs when the percentage of used disk has exceeded [write-blocking-thresholds](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections), and Atlas has [blocked writes](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections) to maintain read availability. You can view disk metrics through [Real-Time Performance Panel](https://www.mongodb.com/docs/atlas/real-time-performance-panel.md#std-label-real-time-metrics-status-tab) and review [MongoDB process metrics.](https://www.mongodb.com/docs/atlas/review-mongodb-process-metrics.md#std-label-review-mongodb-process-metrics) - [`Writes have been unblocked on your cluster`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-Writes-have-been-unblocked-on-your-cluster) occurs when the percentage of used disk on the primary node has fallen below the [unblocking thresholds](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections), and Atlas automatically unblocks writes to the cluster. See also [Unblocking Writes.](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections) This is an information-only alert that doesn't require any action on your part. To prevent future write-blocking events, we recommend that you monitor your cluster's disk usage. To learn more, see [Preventing Write-Blocking.](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections) ## Alert Conditions You Can Configure You can configure the following alert condition in the project-level [alert settings](https://www.mongodb.com/docs/atlas/configure-alerts.md#std-label-configure-alerts) page to trigger alerts. [`Disk space % used on Data Partition`](https://www.mongodb.com/docs/atlas/reference/alert-conditions.md#mongodb-alert-Disk-space---used-on-Data-Partition-is) occurs when the percentage of disk space used on any partition that contains the MongoDB collection data meets or exceeds a certain threshold. [By default](https://www.mongodb.com/docs/atlas/configure-alerts.md#std-label-default-alert-settings), the threshold is 90 percent of the cluster's [configured storage size.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster) ## Common Triggers The following common events can trigger `Disk Space % Used` alerts: - The percentage of used disk has exceeded [write-blocking-thresholds](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections), and Atlas has [blocked writes](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections) to maintain read availability. - The disk is full and [Auto-Expand Storage](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-storage) is not enabled. - Auto-Expand Storage is enabled, but the disk filled too quickly for Atlas to expand the cluster's storage space. This can happen during data migration. - Auto-Expand Storage is enabled, but Atlas cannot expand the cluster's storage space because it has reached the maximum storage capacity for this cluster. For more information on cluster tier limits, see the [Amazon Web Services](https://www.mongodb.com/docs/atlas/reference/amazon-aws.md#std-label-amazon-aws-configuration-options), [Google Cloud Platform](https://www.mongodb.com/docs/atlas/reference/google-gcp.md#std-label-google-gcp-configuration-options), and [Microsoft Azure](https://www.mongodb.com/docs/atlas/reference/microsoft-azure.md#std-label-microsoft-azure-configuration-options) instance configuration options. ## Fix the Immediate Problem Consider the following actions to help resolve `Disk Space % Used` alerts through the Atlas UI or API. ### Atlas UI - [Enable Auto-Expand Storage.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-storage) **Note:** If the disk fills too quickly, Atlas might not be able to expand the cluster's storage space in time, even if Auto-Expand Storage is enabled. - Manually increase the Storage of this cluster in the Cluster Tier section of the [configuration page.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-storage) ## Implement a Long-Term Solution Consider the following long-term solutions to help resolve `Disk Space % Used` alerts through the Atlas UI or API. ### Atlas UI If you have reached the maximum storage capacity for this cluster, scale to a larger cluster tier in the Cluster Tier section of the [configuration page.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-instance) ## Monitor Your Progress You can observe a high percentage of used disk space in the following ways: - In the cluster [metrics](https://www.mongodb.com/docs/atlas/monitor-cluster-metrics.md#std-label-monitor-cluster-metrics), the Disk Usage graph displays the used disk space in yellow. This indicates that the used disk space is approximately 70 percent of the Atlas cluster's [configured storage size.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-instance) - Atlas nodes are unhealthy, because the used disk space reached the cluster's [configured storage size.](https://www.mongodb.com/docs/atlas/scale-cluster.md#std-label-scale-cluster-instance) - The cluster [blocks writes](https://www.mongodb.com/docs/atlas/intelligent-workload-management.md#std-label-iwm-always-on-protections) and connections from the client.