ArcGIS Pro and Microsoft 365 storage

Q: What happens to file geodatabases (.gdb) when they are stored in OneDrive?

A file geodatabase is a directory (with a .gdb extension) that contains dozens of internal files representing feature classes, tables, indexes and metadata. OneDrive sync treats the internal files as independent objects and syncs them one at a time. If ArcGIS Pro writes to the geodatabase mid-sync, or if OneDrive uploads a partial state, the geodatabase can end up in an inconsistent state that ArcGIS Pro then refuses to open. This is the primary cause of GIS teams reporting geodatabase corruption after cloud migration.

Q: Do ArcGIS Pro projects (.aprx files) resolve their linked datasets on a mapped drive?

Yes. .aprx files store references to source datasets by path. If every user has the same drive letter mapped to the same SharePoint site (which is the standard CDM deployment), an .aprx file opens with all its layers linked and resolved. This is materially better than the OneDrive-synced pattern where the same .aprx file may resolve differently on different users' machines depending on the state of their local sync cache.

SOLUTION GUIDE

ArcGIS Pro is unusually unforgiving of cloud file storage because its data model is multi-file by design. File geodatabases (.gdb) are directory structures containing dozens of internal files that must be consistent with each other. Shapefiles ship as five or six related files sharing the same basename that must move together. ArcGIS Pro projects (.aprx) reference external datasets by path. When any of these datasets sit in OneDrive-synced folders, the sync client sees each constituent file as independent, and mid-write partial syncs corrupt or fragment the dataset. Cloud Drive Mapper presents SharePoint as a mapped drive so ArcGIS Pro treats Microsoft 365 storage the way it treats a traditional file server: all components of a dataset visible together, stable paths across users, no sync-timing risk.

What breaks when ArcGIS Pro runs on OneDrive-synced storage?

Five patterns account for almost all of the GIS-specific pain. Utility and government GIS teams tend to see three or four of them within their first project stored in OneDrive-synced storage.

File geodatabase corruption

A file geodatabase (.gdb) is a folder full of internal files representing feature classes, tables, spatial indexes and metadata. When ArcGIS Pro writes to a geodatabase, it updates multiple internal files as part of a single logical operation. OneDrive sync treats those internal files as independent objects and syncs them one at a time. If sync uploads a partial state (some updated files, others not yet updated), the geodatabase in the cloud is internally inconsistent, and ArcGIS Pro refuses to open it or reports schema errors when it does. This is the single most common failure mode of GIS on OneDrive.

Broken shapefiles

A shapefile layer needs all of .shp, .shx, .dbf, .prj, .cpg (and sometimes .sbn/ .sbx) present, consistent, and with the same basename. OneDrive sync can lag on any of them. Users see a layer that opens but shows no features (dbf out of sync), or a layer that opens with the wrong projection (prj not updated yet), or an error where the geometry is present but the attribute table is not.

ArcGIS Pro projects with broken data source links

An .aprx project file stores absolute or relative paths to its source datasets. When those source datasets shift between OneDrive-synced and stub states, or when different users' machines are at different points in their sync cycle, the project opens with red exclamation marks against layers whose data cannot be found. Time is then lost re-pathing layers instead of doing GIS work.

Locked files during sync

OneDrive briefly opens files during upload. If ArcGIS Pro is trying to write to a file (or read it for a rendering operation) at the moment OneDrive is uploading it, the operation fails with a file-in-use error. Users retry; sometimes it works, sometimes the file is now inconsistent.

Large rasters and imagery bloat the sync cache

Utility asset-management datasets and government imagery libraries frequently include rasters running to many gigabytes. Sync-client behaviour of "download the whole file to work with any part of it" is a poor fit for analysis workflows that only need a small area of the raster. Local disk fills up, sync bandwidth is saturated, and workstations slow down.

Why ArcGIS Pro needs a real filesystem

GIS data is not a single file; it is a set of related files that must be consistent at every point in time. That constraint holds for geodatabases, shapefiles, coverage datasets and many raster formats. Network file shares meet the constraint because a directory is a directory: every file in it is reachable together, exclusive locks are honoured, and no third party is moving files around mid-session. The OneDrive sync client trades those guarantees for cloud availability, and for typical office documents that is a fair trade. For GIS it is not, because GIS's atomicity assumption is stronger than the sync client's consistency model.

For the broader take on why sync clients struggle with applications that expect real filesystem behaviour, see Desktop applications and real file paths. ArcGIS Pro's multi-file datasets are one of the sharpest illustrations of the pattern.

How Cloud Drive Mapper fits with ArcGIS Pro

Real Windows drive letters and stable paths

CDM maps SharePoint document libraries as drive letters (M:, N:, whatever you configure). ArcGIS Pro opens datasets from the mapped drive the same way it would from a network share. .aprx projects resolve their linked layers consistently across users because the drive letter is stable across the whole GIS team.

File geodatabases stay consistent

The .gdb directory and its internal files are accessed atomically through CDM. There is no sync client partial-uploading some files while ArcGIS Pro is writing to others. Geodatabase corruption of the "sync ate my indexes" flavour goes away.

Shapefile bundles stay together

Every constituent file of a shapefile is reachable at the same time from the mapped drive. There is no scenario where the .dbf is available but the .shp is a not-yet-hydrated stub, so shapefile layers open with all their attributes and geometry intact.

Large rasters stream on demand

CDM streams file content rather than syncing a full local mirror. Opening a large raster downloads only what ArcGIS Pro requests for the current view. A utility team can work against a 20GB imagery mosaic without pulling the whole file to the local disk.

Toolboxes and Python scripts resolve consistently

Custom toolboxes and Python scripts referenced from .aprx projects use file paths. On a standardised CDM drive letter those paths resolve the same way for every user in the team, and shared script libraries stay consistent.

ArcGIS Pro-specific setup notes

Standardise the CDM drive letter across every GIS analyst's workstation so .aprx project links resolve identically.
Store enterprise geodatabases and Esri connection files in the SharePoint library mapped through CDM. Every analyst opens the same source-of-truth data.
For very large enterprise GIS deployments, an enterprise geodatabase (SDE / ArcGIS Enterprise) hosted on a proper database platform remains the right answer, and CDM sits alongside for the file-based supporting content (shapefile deliverables, project files, imagery, scripts).
Update Python script file-path references from OneDrive-synced folders to the CDM drive letter.
If migrating from a previous OneDrive-synced setup, run ArcGIS Pro's Recover File Geodatabase tool on any geodatabases that showed schema errors before moving the recovered version to CDM.

CDM supports ArcGIS Pro in the following deployment models:

Windows desktops (direct)
Citrix Virtual Apps and Desktops
Citrix DaaS
Azure Virtual Desktop (AVD)
Windows 365 Cloud PC
Omnissa Horizon (formerly VMware Horizon)

Cloud Drive Mapper is used across utilities, government agencies and planning teams to keep ArcGIS Pro workflows working cleanly against Microsoft 365 storage.

Start a 30-day free trial How Cloud Drive Mapper works →

Frequently asked questions

Does ArcGIS Pro work with Microsoft 365 storage through Cloud Drive Mapper?

Yes. CDM presents SharePoint as a Windows mapped drive letter. ArcGIS Pro opens geodatabases, shapefiles, ArcGIS Pro project files (.aprx) and raster datasets from the mapped drive the same way it would from a network file share. Multi-file dataset relationships hold because all component files are always visible together in the same path.

What happens to file geodatabases (.gdb) when they are stored in OneDrive?

A file geodatabase is a directory (with a .gdb extension) that contains dozens of internal files representing feature classes, tables, indexes and metadata. OneDrive sync treats the internal files as independent objects and syncs them one at a time. If ArcGIS Pro writes to the geodatabase mid-sync, or if OneDrive uploads a partial state, the geodatabase can end up in an inconsistent state that ArcGIS Pro then refuses to open. This is the primary cause of GIS teams reporting geodatabase corruption after cloud migration.

Do shapefiles need special handling?

A shapefile is not a single file: it is a set of five or six related files sharing the same basename (.shp, .shx, .dbf, .prj, .cpg, sometimes .sbn/.sbx). All of them must be present and consistent for ArcGIS Pro to open the layer. OneDrive sync can lag on some of the constituent files while others are already updated, producing a broken layer. Storing shapefiles on a CDM-mapped drive avoids this because all constituent files are reachable atomically from the mapped path.

Do ArcGIS Pro projects (.aprx files) resolve their linked datasets on a mapped drive?

Yes. .aprx files store references to source datasets by path. If every user has the same drive letter mapped to the same SharePoint site (which is the standard CDM deployment), an .aprx file opens with all its layers linked and resolved. This is materially better than the OneDrive-synced pattern where the same .aprx file may resolve differently on different users' machines depending on the state of their local sync cache.

Do large rasters and imagery datasets perform on CDM?

Yes. CDM streams file content on demand rather than syncing a full local mirror. Opening a large raster (aerial imagery, elevation model, tile package) downloads only what ArcGIS Pro requests for the current view; you do not need to pre-download the whole file to open the project. This is important for utility asset-management datasets and government imagery libraries where individual rasters can run to many gigabytes.

Does IAM Cloud have access to our GIS data?

No. Cloud Drive Mapper operates purely with delegated permissions inside your Microsoft 365 tenant. IAM Cloud holds no credentials that would authenticate to your tenant. Only your own signed-in users can access content through CDM, and only within their existing M365 permissions. See Zero-access architecture for the design detail.

Try it with your GIS estate

The fastest way to see if CDM fits your ArcGIS Pro setup is to try it for 30 days, free. Move a small file geodatabase and a project file to a mapped drive, and open them from ArcGIS Pro.

Start a free trial Request a demo