Problem Summary:
During backup of FSx for Windows File Server using Druva NAS workload, some files are skipped with "Permission Denied" errors. These files appear valid but do not behave like standard symbolic links during the backup process.
Cause:
Symbolic links hosted on FSx and accessed over the SMB protocol may not expose proper symbolic link metadata. As a result:
File attributes are shown as “Normal” instead of expected link attributes (e.g., SYMLINK or REPARSE_POINT).
PowerShell commands (e.g., Get-Item) show no link type for these files.
The operating system and backup tools interpret these files as ordinary files, not as symbolic links.
This behavior is consistent with AWS documentation stating that FSx for Windows File Server accessed over SMB does not support symbolic link preservation in certain scenarios, such as with AWS DataSync.
Resolution:
1. Verify File Attributes:
Use PowerShell:
Get-Item -Path <file-path> | Format-List *
Confirm whether the files expected to be symbolic links are not recognized as such.
2. Understand FSx SMB Limitations:
Review the AWS limitations on symbolic link handling with SMB:
3. Workaround Options:
Switch to NFS (if applicable):
Accessing FSx for Windows via NFS protocol may properly expose symbolic link metadata to backup tools.
Directory Exclusion:
If symbolic links are located in specific paths, exclude those directories from backup jobs to prevent errors.
File Handling Strategy:
Design your backup approach with awareness of symlink behavior, including their exclusion or conversion into actual files.
4. Review Backup Environment:
Confirm the backup proxy or SMB client:
Has the necessary permissions to access reparse points (if any).
Supports advanced file metadata exposure over SMB.
Verify the SMB version compatibility between client and FSx:
Some link metadata may not propagate properly on older SMB versions.
Key Takeaway:
Symbolic links on FSx for Windows accessed via SMB are not reliably supported for backup or metadata detection. Backup tools may treat them as regular files, leading to access issues or skipped files.
For environments that require symbolic link awareness or preservation, consider:
Switching to NFS access, or
Adjusting the backup inclusion/exclusion strategy.