claudetools/.claude/memory/reference_sharepoint_graph_large_file_upload.md

name, description, metadata

name	description	metadata
sharepoint-graph-large-file-upload	Uploading files to SharePoint via Graph — simple PUT <4MB, chunked upload session >=4MB; verify counts via delta	type reference

Pushing a folder tree into a SharePoint doc library via Microsoft Graph (app-only):

• <4MB: simple PUT /drives/{drive}/root:/{path}:/content.
• >=4MB: MUST use an upload session — POST .../root:/{path}:/createUploadSession then PUT the file in chunks (multiple of 320 KiB; 10 MB works) with a Content-Range: bytes {start}-{end}/{total} header. In PowerShell 5.1 Invoke-RestMethod -Headers @{ 'Content-Range'=... } handles this fine. A naive script that only does <4MB PUTs will silently skip every large file and never reach the target count.
• Long Windows paths (>260): prefix the local path with \\?\ for [IO.File] reads.
• Idempotent sync: existence-check each file (GET root:/{path}?$select=size) and skip if size matches — this also catches/repairs partial-upload residue from earlier failed runs.
• Throughput: a single sequential upload stream to SharePoint Online plateaus ~40 Mbps regardless of link speed (per-session SPO throttle + PS5.1 HTTP stack + Expect100Continue). For speed use parallel file streams + larger chunks + Expect100Continue=$false.
• Verify total file count with the Graph delta endpoint (/drives/{drive}/root/delta) — whole-drive enumeration in a few paged calls, far cheaper than recursive /children.

Proven end-to-end on Birth Biologic Quality Systems (3,768 files, 301 >=4MB, ~29.7 GB; largest 3.94 GB). Dispatched via GuruRMM — see gururmm-command-timeout-seconds.