BA4931: Unable to create catalogue using MFT parser¶
| Error code | Product | Applies to |
|---|---|---|
| BA4931 | BackupAssist | For BackupAssist 15.0.0 or later. |
Description¶
Unable to create catalogue by using MFT parser for the Hyper-V guest. The legacy (slow) traverser was used instead.
Resolution¶
BackupAssist could not read the Hyper-V guest volume's Master File Table (MFT) to build the catalogue quickly, so it fell back to the slower legacy traverser. The backup still completed - this is about restoring the faster catalogue path. It is usually caused by minor NTFS inconsistencies inside the guest volume.
From within the Hyper-V guest, at an elevated command prompt, run a check-disk on the affected volume - for the volume with drive letter X, run "chkdsk X: /f". Note that "chkdsk /f" needs exclusive access and dismounts the volume; on the guest's system volume it runs at the next restart of the guest, so schedule it outside backup and production hours. Once the guest volume is clean, MFT parsing is used again on the next backup.
To keep using the legacy traverser instead, Support can direct you to a registry value (DisableMFTParsingForHyperVGuests) on the host.
| Last updated | Created | Further assistance |
|---|---|---|
| 15th Sep 2026 | 6th Nov 2025 | BackupAssist Support page |