Why can't I copy large files to external hard drive?
For security or portability reason, you may want to store important data on a removable device, but end up finding the file too large to copy to external hard drive or USB, even when there's sufficient space in it. Why did this happen, and how to transfer large files to external hard drive successfully?
Well, one possible reason is that the file is really larger than the available space of the external hard drive. But the most likely situation is as in this case - the file is too large for the destination file system.
It happens because each file system has its own size limitation. FAT (also known as FAT16) only supports a file up to 2 GB, FAT32 supports up to 4 GB, as for NTFS, the maximum file size is 16 TB. You can’t transfer a file that exceeds the limit of the destination drive even when it has plenty of spare space. Such being the case, you can take following measures to fix the problem and copy large files smoothly.
How to fix the problem that a file too large for external hard drive
If you fail to copy large files to external hard drive or USB, you should check the available space and file system of the destination drive at first, and then pick a solution according to your case.
Method 1. Check your external hard drive or USB
Anyway, first check that your device is connected properly and make sure it really has more available space than the file you want to copy. If not, you can take the most direct way – prepare another external hard drive or USB flash drive with sufficient space. If you don’t have any large device, please refer to Method 4.
Method 2. Convert the file system to NTFS
If you receive the file too large for the destination file system message while the external hard drive has sufficient space, the first possibility is your destination drive has been formatted to FAT/FAT32, which has a maximum size limit of 2 GB/4 GB. Thus you can’t transfer large files beyond the amount unless you convert the file system to NTFS.
★ Check the file system information: First open the File Explorer > right-click the external hard drive > choose Properties > find File system under General tab.
★ Convert file system without losing data:
If you’ve stored some files in the external hard drive, this may be the best way to convert file system without data loss.
1. Press Windows logo key + R at the same time. Type cmd in the box and click OK.
2. Type the command: convert n: /fs:ntfs (“n” refers to the drive letter of external hard drive).
3. Press Enter key to run it, and enter the volume label (name) if required. Within a few minutes, FAT32 formatted external hard drive will be converted to NTFS successfully. Then you can copy large files to it as normal.
★ Re-format the drive directly:
This solution can help you convert FAT/FAT32 to NTFS or vice versa, but it will erase all data on the drive. Therefore, you’d better backup external hard drive before formatting.
1. Open File Explorer, right-click the drive and choose Format...
2. Find File system select box in the popping out windows, choose the option you want from the drop-down menu. Here choose NTFS.
3. Click Start and then OK to confirm the operation. Wait for a while, this external hard drive will be converted to NTFS successfully.
Method 3. Re-connect the external hard drive or USB
If you find the file too large for destination file system when the drive is already NTFS formatted, it’s probably because it's still identified as FAT/FAT32. Then you can try reconnecting the drive without physically unplugging it.
1. Right-click Start button and choose Device Manager, or directly search for it.
2. Find the external hard drive or USB drive in the list, right-click it and choose Disable.
3. Wait for a while and then Enable it.
Alternatively, you can open Disk Management, right-click the drive and choose Eject. And to re-connect it, you need to change its status to Online.
Method 4. Backup a large file to external hard drive directly
Except for above ways, you can still directly backup larger files to external hard drive with a practical software like AOMEI Backupper Standard. It will split the backup file to 4GB or 2GB automatically if the target drive is formatted as FAT32 or FAT file system and copy files without converting file system. Below are some advantages you can enjoy in the following:
- Backup large files automatically: It allows you to backup larger files with daily, weekly, monthly schedule backup, thus you don't need to worry about data loss due to forgetting backup.
- Backup only changed files: Instead of backing up all files, this software will backup changes only with incremental backup if you set a scheduled task.
- Greatly reduce the size of backup image: Except for splitting large image into multiple smaller files, you can still enjoy normal compression, intelligent sector backup, etc to minimize backup size.
Download it to have a try if you use Windows 11/10/8/7/XP/Vista. For server users, try AOMEI Backupper Server.
You can effortlessly use the software for continuous data protection, and once there’s an image file too large to transfer to USB or external hard drive, this software will take care of this automatically by splitting image to 4GB or 2GB. Please follow the steps to copy large files to FAT32 external hard drive without converting file system.
1. Open AOMEI Backupper, go to the Backup tab, and choose File Backup.
2. Click Add Folder or Add File to locate the folders or files you want to backup to external hard drive.
3. Select the connected external hard drive as the destination.
4. Click Options > Advanced > Splitting to specify the size you want to split the image file into and click OK to confirm it. Alternatively, you can keep using the Automatic Splitting feature, it will split backup image to 4GB or 2GB depending on the file system of target disk. Then, click Start Backup to backup large files to external hard drive.
If you want to customize size as you like, you need to upgrade to the Professional edition. Please note the minimum image file size is 50MB. And you can further shrink the image file with a high compression level as well as enable email notification, comment, split, etc in the Options feature.
Also, you can set more advanced feature to excute this task automatically and flexibly. To keep large files and changes made later, you need to set Schedule Backup and backup files automatically. You can choose among Daily, Weekly, Monthly, Event trigger, and USB Plug in. The last two premium features are available on the professional version.
By default, this software will create one full backup and 6 incremental backup if you set a scheduled backup task. This may result in the backup disk full issue in the long run, thus it's suggested to enable Backup Scheme and delete backup file automatically. You have 3 options, By quantity, By time, By daily/weekly/monthly. You need to upgrade now (5% off for one computer) before using it.
And the incremental backup has a high requirement for recovery while the differential backup is much easier. For differences between them, learn from my previous article: Incremental or Differential Backup.
After splitting, it’s recommended to keep these image files in the same directory to ensure the convenience of data management.
Don't panic when your file is too large to copy to external hard drive. Take some time to try the above methods, or use AOMEI Backupper Standard to backup the large file to external hard drive automatically. Considering external hard drives could be damaged or lost easily, you can use this freeware to backup files to cloud drives, network or NAS devices as well.
In addition, if you want to copy a partition or a disk for hard drive replacement, the Clone feature also comes in handy. With the intelligent clone technology, you can even clone a larger drive to a smaller SSD.