Can Lightroom corrupt DNG files when writing XMP metadata to a network drive?
Asked 1/14/2014
3 views
2 answers
0
I’m using Lightroom 5 on Windows 8.1 with DNG files stored on a network drive. The original RAW files were fine, and the converted DNGs initially worked normally. After editing and using Lightroom’s auto-save/XMP write behavior, some images started showing a gray exclamation mark with the error: “An unexpected end of file occurred.”
The image data appears intact, but the XMP metadata at the end of the DNG seems truncated. For example, one damaged file ends mid-tag:
photoshop:DateCr
I’d like to know:
- Is Lightroom known to corrupt DNGs when writing metadata, especially over a network drive?
- Is this more likely a network/write failure than a Lightroom bug?
- Is there any way to repair or strip the broken XMP metadata so Lightroom can read the files again?
Moving to a local working drive is now planned, but I’d still like to understand the likely cause and best practice.
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
12y ago
2 Answers
2
Sounds to me that it is more likely to have been a failure saving the file over the network. Network backups are nice for archival storage, but horrible for live work due to the extremely slow load times for relatively large files.
The process I generally use is to initially transfer my files to my high speed scratch SSD array (striped). I then immediately copy the files to my external long term archive drive (RAID 5 array) prior to doing any work on the files. (I use an eSATA enclosure connected over USB3 rather than a network, but the principal is the same.) After the files are backed up to the external, I am free to do whatever I need and can simply save off the Lightroom catalog with all the changes at the end of working through the set.
This ensures quick load times and an expedient working environment while also minimizing the risk of data loss or corruption issues, both because of the long-term backup of the originals as well as the fast, local performance of the SSD working drives.
Originally by user11392. Source · Licensed CC BY-SA 4.0
user11392
12y ago
0
Generated from our catalog & community — verify before relying on it.
This is more likely a failed write over the network than Lightroom uniquely “corrupting” DNGs. Your clue is that the image data seems intact while the embedded XMP at the end of the DNG is cut off, which strongly suggests Lightroom started updating metadata and the save did not complete.
Network storage is fine for backup/archive, but it’s a poor choice for active editing because interruptions, latency, or incomplete writes can leave large files in a partially updated state. Best practice is to work from a fast local drive, then copy/backup to redundant storage.
For Lightroom workflows, it’s generally safer to rely on the Lightroom catalog during active editing and back that up regularly, rather than constantly writing metadata back into the files on network storage.
If the file’s embedded metadata is truncated, recovery may be limited. If you still have the original RAWs or earlier good DNG copies, those are your best source. In short: the likely cause is an interrupted network save, and the practical prevention is local editing plus separate backup/archive storage.
Recommended products
UniqueBot
AI12y ago
Your Answer
Related Questions
How can I identify corrupt RAW files that trigger Lightroom's 'unexpected end of file occurred' error?
Why are some DNG files smaller than the original camera RAW files?
Can Lightroom batch-compress existing DNG files in a catalog?
Can multiple editors store separate non-destructive edits in the same DNG file?
Why won’t some Lightroom-converted DNG files show thumbnails or open in Preview on older macOS?