Scan Synology NAS for File Paths Exceeding SharePoint Migration Limits

Manual walkthrough — enable SSH and run the scan on the Synology

This is a command-line task at its core, but the GUI steps below get you to a shell prompt on the NAS.

1. Enable SSH on DSM

1. Sign in to DSM as an administrator.
2. Open Control Panel → Terminal & SNMP → Terminal.
3. Check Enable SSH service. Leave the port at 22 (or change it and note the new port).
4. Click Apply.

2. Connect via SSH

1. From a Windows, macOS, or Linux workstation, open a terminal (Windows Terminal, PuTTY, iTerm, etc.).
2. Run: ssh admin-user@<nas-ip-or-hostname>
3. Accept the host key and enter the administrator password.

3. Run the path-length scan

1. At the shell prompt, run the following (replace the path and threshold as needed):

   sudo find /volume1/YourShare -print0 | \
     while IFS= read -r -d '' p; do \
       len=${#p}; \
       if [ "$len" -gt 350 ]; then \
         printf '%d\t%s\n' "$len" "$p"; \
       fi; \
     done | sort -rn > /volume1/YourShare/_long_paths.tsv

2. Wait for the prompt to return. On a multi-terabyte share this can take several minutes.
3. Open File Station in DSM, navigate to the share, and download _long_paths.tsv.
4. Open the file in Excel (tab-delimited) — column A is the path length, column B is the full path, sorted longest first.

4. Disable SSH (optional but recommended)

Return to Control Panel → Terminal & SNMP → Terminal and uncheck Enable SSH service if it is not normally on.

Not applicable for this recipe. Synology DSM does expose a Web API, but it does not provide a filesystem-traversal endpoint that returns full paths for every file on a volume. A path-length audit is fundamentally a recursive filesystem walk, which is best done with shell access on the NAS (see the Bash script section) or from a mounted client. Use the shell approach above instead.

Script approach — two options

Pick whichever is easier given your environment. The Bash option is preferred; the PowerShell option is a fallback for Windows-centric shops.

Option A: Bash on the Synology (recommended)

Save the downloadable script below as scan-long-paths.sh, copy it to a share on the NAS (e.g. /volume1/homes/admin/), and run it over SSH:

chmod +x scan-long-paths.sh
sudo ./scan-long-paths.sh /volume1/YourShare 350 /volume1/YourShare/_long_paths.tsv

Arguments:

• $1 — root path to scan (required)
• $2 — character threshold (default 400)
• $3 — output file (default ./long_paths.tsv)

Output is a tab-separated file: length<TAB>full_path, sorted longest first.

Option B: PowerShell from a Windows workstation

If the Synology share is already mounted (e.g. Z:\) or reachable via UNC (\\nas01\YourShare), run this from an elevated PowerShell prompt:

$Path  = '\\nas01\YourShare'
$Limit = 350
$Out   = "$HOME\Desktop\LongPaths.csv"

Get-ChildItem -LiteralPath $Path -Recurse -File -Force -ErrorAction SilentlyContinue |
  Where-Object { $_.FullName.Length -gt $Limit } |
  Select-Object @{N='Length';E={$_.FullName.Length}}, FullName |
  Sort-Object Length -Descending |
  Export-Csv -LiteralPath $Out -NoTypeInformation -Encoding UTF8

Caveat: Windows PowerShell 5.1 can fail on paths that are already over ~260 characters because of the legacy MAX_PATH limit. Use PowerShell 7+ (which is long-path-aware by default) or prefix paths with \\?\. When in doubt, fall back to the Bash script run on the NAS itself.

Interpreting the output

• Sort by length descending and start remediation with the worst offenders.
• Group by parent folder — often a single deeply nested project folder is responsible for hundreds of long paths, and re-homing that one folder fixes all of them.
• Re-run the scan after remediation to confirm zero results above your target threshold before starting the migration.