# How to troubleshoot D:\ drive full on the NovaSeq 6000

**Note**: It is normal for this drive to appear red when viewed in the file explorer. Use the following troubleshooting steps only if the drive is completely full.

* A new run might not be able to start due to lack of space on the D:\ drive, despite no runs being present in Process Managements or on the instrument.
* Lack of space on the D:\ drive can impact the functioning of Universal Copy Service (UCS) and data transfer. This can manifest as Universal Copy Service stopping run transfer mid-run.
* If a run continues to progress but data transfer fails, collect Universal Copy Service logs located under C:\ProgramData\\\*\Illumina\UniversalCopyService\ and contact [Illumina Technical Support](https://www.illumina.com/company/contact-us.html#/united-states/technical-support) for the next steps.

\\\*The ProgramData folder may be hidden; select the View tab in the file explorer window to un-hide files and ensure “Hidden items” is checked.

**Cause**:

* The D:\ drive is for long-term health/performance data storage and gets filled over time.
* When runs are deleted via Process Management, it only wipes the oldest 8 Gb of data for runs. However, some run types save more than 8 Gb of performance data; for example, S4 runs push a total of approximately 10 Gb of data to the D drive.

**Troubleshooting steps:**

* It is important to leave as much of the data on this drive as possible.
* If the D drive fills up, delete the oldest run files and/or any .imf1 files that are older than 3 months from D/Illumina/instrument Analytics until there is a total of 16 Gb of space available.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #1273), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000001273%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |