When you need to transfer a large number of files at once (such as archiving historical files or migrating data from an another system) to OmniStor, dragging and copying files directly using OmniStor Drive may not be the most efficient method. This article provides three bulk transfer methods and guidance on how to choose among them.

Overview of Three Methods

Important Notes

Before Uploading, Confirm

• Sufficient OmniStor cloud quota: Check the remaining space in your OmniStor Web account information first.
• Sufficient C drive space: If uploading via OmniStor Drive (applicable for robocopy, xcopy), the C drive needs temporary space.
• Stable network: Bulk transfers take a long time; unstable network may cause partial failures.

During Transfer

• Do not shut down or let the computer sleep: Maintain connection throughout the bulk transfer.
• Avoid simultaneous operations on OmniStor Drive: May cause sync conflicts.
• Regularly check progress: Use the tool's progress display to confirm status.

After Transfer Completion

• Verify file count and size: Compare source and destination.
• Spot-check important files: Open a few files to confirm content integrity.
• Check Problem Files: Any failed uploads will be stored here (applicable for robocopy, xcopy).

Method 1: Use OmniStor Built-in FTP

FTP is the fastest method for the first bulk data transfer.

OmniStor provides an FTP interface specifically designed for bulk data transfers. Uploading via FTP tools is faster than dragging and dropping files using OmniStor Drive.

How to Use

1. Obtain FTP service connection info: Contact your organization's system administrator to confirm OmniStor FTP service URL, port, username, and password.
2. Prepare FTP tool: Use software that supports FTP/sFTP/FTPs, such as cuteFTP, FileZilla, etc.
3. Connect and upload: Use the tool to connect to OmniStor FTP and upload the files to the corresponding location.

After completion, these files will appear in your OmniStor space — accessible via OmniStor Drive, Web, or Mobile App.

For detailed FTP connection settings, please refer to the ASUS Cloud OmniStor for FTP Client User Manual.

Method 2: Use Robocopy

When moving files from an old disk to the OmniStor Drive virtual disk, Drive sync copies a large number of files to OmniStor. Robocopy is preferred over xcopy.

Why Choose Robocopy?

• Repeated file mirror comparison: Accurately determines which files need copying and which can be skipped.
• Automatic space detection: Detects disk space and automatically pauses if space is insufficient, preventing data corruption during interruptions.
• More stable: Suitable for large numbers of files and long copy durations.

Basic Usage

Robocopy is a built-in Windows tool (available by default from Windows 7 onward), accessible via Command Prompt:

robocopy [source] [destination] [parameters]

Common example:

robocopy D:\OldData W:\MySyncFolder\Archive /E /Z /R:3

• /E: Copy all subdirectories (including empty ones).
• /Z: Restartable mode (can resume after network interruption).
• /R:3: Retry 3 times on failure.

For detailed parameters, please refer to the official Microsoft Robocopy documentation.

Method 3: Use xcopy (Simple One-Time Transfer)

xcopy is a lightweight, simpler file copy command suitable for one-time, smaller-scale copy tasks. However, it has limitations in resume after interruption, retry on failure, differential comparison, error logging, and handling large numbers of files. If copying a small number of clearly defined files, xcopy can be used; for long-running, large-scale transfers or where higher stability and traceability are required, robocopy is recommended.

For example: data volume within about 500 MB and fewer than 5,000 files.

Basic Usage

xcopy [source] [destination] [parameters]

Common example:

xcopy D:\OldData W:\MySyncFolder\Archive /E /I /Y

• /E: Copy all subdirectories (including empty ones).
• /I: If destination does not exist, create as directory.
• /Y: Overwrite without prompting.

Which One Should You Choose?

Transferring to OmniStor cloud
├── Is this the "first large transfer"?
│    └── ✓ Use FTP
├── Is this "local to local, then sync via OmniStor Drive"?
│    ├── Large number of files, need repeated comparison → Robocopy
│    └── Simple one-time, small scale → xcopy
└── Very small amount (

Frequently Asked Questions

Q: Can I use Robocopy to copy directly to the OmniStor Drive disk?

A: Technically possible, but it still uses OmniStor Drive’s streaming upload mechanism — speed is similar to dragging and dropping, so it doesn’t save time. The manual recommends using FTP for the first large transfer for this reason.

Q: If transferring several TBs of data, will FTP also be slow?

A: FTP is still limited by your network bandwidth. However, compared to OmniStor Drive’s streaming upload, FTP has a shorter path and lower overhead, so it’s generally faster. For extremely large amounts of data (several TBs or more), it’s recommended to discuss with your administrator about other offline transfer solutions.

Q: I’ve heard of both xcopy and Robocopy — what’s the difference?

A: Simply put: Robocopy is an advanced version of xcopy, with more features and better fault tolerance.

Q: Can I delete source files after transfer completion?

A: It’s recommended to verify integrity before deleting. Verification methods:

• Confirm file count matches source on OmniStor Web.
• Sample download a few important files to ensure they open properly.
• Confirm no files remain in Problem Files.

Still Having Issues?

If you encounter problems during bulk transfer, provide the following information to your administrator:

• Transfer method used (FTP / Robocopy / xcopy / OmniStor Drive direct drag-and-drop).
• Total data volume (file count and size).
• List of failed files (if any).
• Error message screenshots.
• Package system logs from OmniStor Drive via 【Settings】→【Log Folder】.