exFAT File System May Corrupt Paragon Backup Files

Challenge

Testing performed in Paragon labs has determined that, in rare cases, Paragon backup files may become corrupted if a local (internal or external) exFAT volume has been selected as backup destination.

Cause

The issue appears to be related to a buffer management (cache flushing) issue in the exFAT file system driver introduced by Microsoft in all versions of Windows 10 and newer (confirmed for all editions of Windows Servers 2016, 2019, and 2022).

The problem occurs whenever the backup image size exceeds the computer’s available physical RAM. The problem doesn’t happen if exFAT is used inside a NAS device or if the backup destination is set as a network SMB shared folder.

There are no similar issues on other, more popular file systems (NTFS, ReFS, etc.).Solution

Based on the detection of this issue, we must strongly discourage using the exFAT filesystem for backup storage when attached to Windows 10 or Windows Server 2016 and later.

Instead, it’s strongly recommended to use NTFS or another journaling file system as local backup destination, or to choose a network location for this sake.

Since exFAT has (like legacy FAT) no files operations journaling, this native data safety limitation makes exFAT file system inappropriate for long time storing of any important data (like backups and other archives). The only purpose of exFAT is data transfer between computers and gadgets managed by different OSes.

More Information

This issue relates to the underlying exFAT filesystem where the backups are stored and can impact any Paragon products capable of storing backup files on such filesystem.