Problem
Two-pass encoding fails because temporary storage fills during the analysis pass.
Solution
Root Cause / Diagnostic:
During the first pass of a two-pass VBR export, the encoder analyzes every frame and generates extensive motion vector statistics, log files, and intermediate raw uncompressed cache data. These temporary cache files are written to the operating system's default temporary directory (usually located on the primary boot SSD). If the boot drive has insufficient free space to house both the analysis cache and intermediate render buffers, the encoder throws an I/O disk full error and terminates the export.
Actionable Fix:
1. In the NLE preferences (Preferences -> Media Cache or encoder scratch disks), redirect temporary media cache and scratch directories to a dedicated secondary high-speed NVMe scratch drive with at least 500 GB of free space.
2. Clean out obsolete media cache files, temp folders, and peak files to free up space on the primary system volume.
3. Relaunch the 2-pass export and monitor scratch drive disk capacity throughout pass 1 to confirm uninterrupted cache writing.
Pro Tip:
Maintain a dedicated, unpartitioned 1TB NVMe drive dedicated exclusively to scratch disks, render previews, and media cache to isolate OS operations from heavy I/O rendering workloads.
During the first pass of a two-pass VBR export, the encoder analyzes every frame and generates extensive motion vector statistics, log files, and intermediate raw uncompressed cache data. These temporary cache files are written to the operating system's default temporary directory (usually located on the primary boot SSD). If the boot drive has insufficient free space to house both the analysis cache and intermediate render buffers, the encoder throws an I/O disk full error and terminates the export.
Actionable Fix:
1. In the NLE preferences (Preferences -> Media Cache or encoder scratch disks), redirect temporary media cache and scratch directories to a dedicated secondary high-speed NVMe scratch drive with at least 500 GB of free space.
2. Clean out obsolete media cache files, temp folders, and peak files to free up space on the primary system volume.
3. Relaunch the 2-pass export and monitor scratch drive disk capacity throughout pass 1 to confirm uninterrupted cache writing.
Pro Tip:
Maintain a dedicated, unpartitioned 1TB NVMe drive dedicated exclusively to scratch disks, render previews, and media cache to isolate OS operations from heavy I/O rendering workloads.