0x80070299: The requested operation could not be completed due to a file system limitation

Error 0x80070299, "The requested operation could not be completed due to a file system limitation", is Windows system error 665. NTFS refuses to write more to one file because that file is split into too many pieces, or because it reached the largest size the volume allows. Copy the file to another drive first, then fix the drive it failed on.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What error 0x80070299 "The requested operation could not be completed due to a file system limitation" means

In File Explorer the window is titled 1 Interrupted Action. Its first line reads: An unexpected error is keeping you from copying the file. Below it is the line that matters: Error 0x80070299: The requested operation could not be completed due to a file system limitation. Backup tools and servers show the same problem as Windows error 665.

The code decodes in one step. 0x8007 marks a plain Windows error, and 0x299 is 665 in decimal. Microsoft's SQL Server support article quotes the same text for error 665 and explains it: NTFS ran out of room to describe where the pieces of one file lie on the disk. It is a limit of the file, not a lack of free space.

Why the operation fails due to a file system limitation: causes in order

Most often one large file has grown in many small steps on a busy drive, so it lies in thousands of separate pieces. Microsoft explains that each piece that is not next to the previous one needs its own entry, and heavy fragmentation exhausts those entries. Less often a backup writes several streams to one drive at once, which interleaves their pieces. Rarely the file really reaches the NTFS size limit.

How to fix error 0x80070299 "file system limitation" in Windows

Fix 1 solves a single failing file in minutes. Fix 2 is for hard disks. Fix 3 is for backup software that keeps hitting the limit. Fix 4 removes compression. Fixes 5 and 6 rebuild the drive and need a full backup first.

Fix 1. Copy the file to another drive, then use the new copy

10 to 60 minutesLow riskOne large file fails to copy, move or grow, on an HDD or an SSD.

A fresh copy is written in large runs, so it ends up in far fewer pieces than the original. Microsoft names copying the file to another volume as a way to reduce the entries and avoid error 665, and says it often works better than defragmenting on an SSD.

1. Close the program that uses the file: the backup app, the virtual machine or the database.
2. Connect a second drive with more free space than the file's size, formatted as NTFS or exFAT.
3. In File Explorer, copy the file to that drive with Ctrl + C and Ctrl + V.
4. If the copy fails with the same error, copy from the program itself: export the virtual machine or start a new full backup on the second drive.
5. Keep the new copy where it is, or delete the original and copy the new file back to the first drive.
6. Open the file in its program to check it works before you delete anything else.

Fix 2. Optimize (defragment) the drive if it is a hard disk

30 minutes to several hoursLow riskThe file sits on a spinning hard disk (Media type: Hard disk drive) that is busy or nearly full.

Defragmenting joins the pieces of files and free space on a hard disk, so the file needs fewer entries. Microsoft adds that on SSDs defragmentation typically does not address this problem, so use Fix 1 there.

1. Close the program that writes to the file, so the file is not in use.
2. Open File Explorer with Win + E and select This PC.
3. Right-click the drive with the file, select Properties and open the Tools tab.
4. Under Optimize and defragment drive, select Optimize.
5. In Optimize Drives, check the Media type column. For Hard disk drive, select the drive and Optimize.
6. Wait until Current status shows OK, then try the copy or backup again.

Fix 3. Split the backup archive or the big file into parts

15 minutes plus a new full backupLow riskA backup, image or retention job fails with 0x80070299 or "Cannot write data to file due to a file system limitation".

Backup archives grow and shrink with every merge and cleanup, so their pieces multiply. Acronis states that retention operations increase the number of pieces and that splitting the archive avoids the limit. Smaller files each have their own list.

1. Open your backup app and find the backup plan's options for splitting or volume size.
2. Turn on a fixed size for each part. Acronis suggests a slice size between 100 GB and 500 GB.
3. Save the plan.
4. Start a new full backup: in Acronis an old archive stays unsplit, so you remove it and create a new one.
5. Keep the old backup until the new one has finished and you can open it.
6. If several backup streams write to the same drive at once, send them to different drives or run them one after another.

Fix 4. Turn off NTFS compression for the folder or drive

10 minutes to an hourLow riskThe file sits in a compressed folder or on a drive with Compress this drive to save disk space ticked.

NTFS compresses a file in small separate units, so a large compressed file that keeps changing can end up in a great many pieces. Without compression the file is written in larger runs. We could not confirm from a Microsoft page how much this adds, so try it after Fix 1 to 3.

1. Make sure the drive has enough free space for the files once uncompressed.
2. In File Explorer, right-click the drive and select Properties.
3. On the General tab, clear Compress this drive to save disk space.
4. Select Apply, choose to apply the change to the drive, subfolders and files, and select OK.
5. For a single folder: right-click it, Properties, Advanced, clear Compress contents to save disk space, then OK and Apply.
6. When it finishes, copy the large file to another drive and back with Fix 1, so it is rewritten in one piece.

Fix 5. Format the backup or data drive with large file records (/L) and 64 KB clusters

1 to several hours, including the backupRead the warningThe error keeps returning on a drive that holds backups, VHDX files or databases, and the drive is not the Windows drive.

Large file record segments make room for more entries per file, which Microsoft says may relieve this problem. A 64 KB cluster also raises the largest NTFS file from 16 TB to 256 TB. Microsoft recommends both for volumes with large files and VHDX files over 1 TB.

1. Copy all data from the drive to another drive and check it.
2. Note the drive letter in File Explorer, for example E:.
3. Open Command Prompt as administrator: How to run a program as administrator or in compatibility mode.
4. Type the command below with your letter and press Enter.
5. Confirm the drive letter and the warning that all data will be lost, and wait for the format to finish.
6. Copy your data back to the drive.

format E: /FS:NTFS /L /A:64K

In PowerShell as administrator the same format is Format-Volume -DriveLetter E -FileSystem NTFS -AllocationUnitSize 65536 -UseLargeFRS. The Format window in File Explorer has no option for large file records, so use one of these commands.

Fix 6. Use ReFS for backup, VM or database storage

2 to 6 hours with the backupRead the warningWindows Server, or a PC that keeps very large VM, backup or database files and can format a drive as ReFS.

Microsoft calls ReFS the best long-term fix, because it does not have the attribute list limit that NTFS has. It only helps for the data you move onto a ReFS volume.

1. Copy all data from the drive to another drive and check the copies.
2. Open Disk Management: right-click Start and select it.
3. Right-click the volume, select Format, and pick ReFS under File system if Windows offers it.
4. Confirm the warning and wait for the format to finish.
5. Copy the backup, VM or database files back.

If error 0x80070299 is still there

Find out which file failed and how big it is. The backup app's log, the SQL Server error log or the Explorer dialog names the file. Then collect these facts before you contact the backup vendor or your IT support.

• The file's full path and size, and the drive's free space.
• The drive type from Optimize Drives (hard disk or SSD) and its File system from Properties.
• Whether the folder or drive is compressed (Fix 4).
• The exact message: 0x80070299, error 665 or "Cannot write data to file".
• Whether the copy to another drive in Fix 1 worked.
• When it is not this limit: Windows offers to scan and fix the drive, or files on it turn unreadable. Then check the drive for damage: Check a disk for errors (chkdsk).

How to stop 0x80070299 from coming back

Frequently asked questions

What does error 0x80070299 mean?

It is Windows system error 665, with the text quoted in the title. NTFS could not write more to one file, because the file is split into so many pieces that its attribute list is full, or because it reached the largest size the volume allows. It is a limit of that file on NTFS, not a lack of free space. Copying the file to another drive is the fastest fix (Fix 1).

Why do I get a file system limitation error when the drive has free space?

Because the limit counts the pieces of one file, not the free bytes. When a large file grows a little at a time on a busy drive, it is stored in many separate pieces. NTFS keeps an entry for each piece, and that list has a fixed size. When it is full, the next write fails even with plenty of free space. A fresh copy or a defragmented hard disk stores the file in fewer pieces.

Does defragmenting fix error 0x80070299 on an SSD?

Usually not. Microsoft says defragmentation works differently on SSDs and typically does not address this problem. On an SSD, copy the file to another drive and, if you want, back again (Fix 1). The copy is written in larger runs and needs fewer entries. Windows still runs its own scheduled optimization (retrim) on SSDs, which is fine to leave on.

Is it safe to run format with the /L option?

The /L option itself is safe, but any format erases the drive. Copy all data off first and check the copies, then run format E: /FS:NTFS /L /A:64K with your drive letter. Do not use it on the drive Windows runs from. Microsoft recommends large file records and 64 KB clusters for volumes with large files, deduplication or VHDX files over 1 TB.

Why does my backup fail with 0x80070299 after working for months?

Each backup, merge and cleanup changes the same large archive, and its pieces add up over time. Acronis says the number of pieces grows during retention operations, until NTFS cannot record more. The fix is to split the archive into parts of 100 to 500 GB and start a new full backup (Fix 3). Formatting the backup drive with large file records helps as well (Fix 5).

Is 0x80070299 caused by the 4 GB FAT32 limit?

No. A file over 4 GB on a FAT32 drive gives a different message, saying the file is too large for the destination file system. Error 0x80070299 comes from NTFS and its record of a file's pieces. If you copy to a FAT32 USB drive and see a size message, format the drive as exFAT or NTFS instead. This page is about the NTFS limit.

What is the largest file NTFS can hold?

It depends on the cluster size. Microsoft lists 16 TB with the default 4 KB cluster, 64 TB with 16 KB, 256 TB with 64 KB and up to 8 PB with 2048 KB clusters on Windows 10 1709 and later. Most readers never reach this size. Error 0x80070299 on a file of a few hundred gigabytes is almost always fragmentation, not size.

What is Xbox error code 0x80070299?

We could not confirm what the code means on an Xbox console. The same number on Windows is the NTFS file system limitation described here. If you see it while copying games to an external drive on a PC, the fixes on this page apply. On the console itself, check the Xbox error code lookup and Xbox Support.

Can I ignore the error and keep using the file?

The file you already have is usually fine; only new writes to it fail. But the program that needs to grow it, such as a backup or a virtual machine, will keep failing until the file is stored in fewer pieces. A backup that cannot finish leaves you without a current copy, so fix it soon with Fix 1 or Fix 3.

The search led me here with a question in another language. Is this the right page?

This page is about the Windows message "The requested operation could not be completed due to a file system limitation", code 0x80070299. If you asked why it happens, the answer is in the section on causes: one large file is split into too many pieces on an NTFS drive. If the error is still there after the fixes, read the section on what to collect for support.