Failed to upload a large VMDK file to vSAN datastore with an error "File #####-flat.vmdk closed with dirty buffers. Possible data loss."

Products

• VMware vSAN

Issue/Introduction

• When attempt to upload a large flat VMDK file to vSAN datastore using vSphere Client, it failed with "File #####-flat.vmdk closed with dirty buffers. Possible data loss".
  
  
• In /var/run/log/vmkernel.log, you will see events similar to:

YYYY-MM-DDTHH:MM:SS.SSSZ cpu26:2103287)WARNING: Res3: 7549: '0d7ce768-ba00-565f-d2ed-3868dd160768': [rt 1] No Space - did not find enough resources after second pass! (needed: 1, found: 0)
YYYY-MM-DDTHH:MM:SS.SSSZ cpu26:2103287)Res3: 7550: '0d7ce768-ba00-565f-d2ed-3868dd160768': [rt 1] Resources t 0, e 0, np 200, wb 0, b 0, RCs u 0, i 0, nf 1305, pe 0, oe 0
YYYY-MM-DDTHH:MM:SS.SSSZ cpu26:2103287)BC: 414: write to #####-flat.vmdk (f530 28 3 68e77c0d 485f99e2 6838936a 680716dd 408d44 2 0 0 0 0 0) 1048576 bytes failed: No space left on device

...

YYYY-MM-DDTHH:MM:SS.SSSZ cpu26:2103287)ALERT: BC: 3177: File #####-flat.vmdk closed with dirty buffers. Possible data loss.

Environment

VMware vSAN

Cause

The default vSAN namespace capacity is limited to 255 GB.
Uploaded flat files are not converted to vSAN objects and therefore are subject to this limitation.

Resolution

After uploading the VM files to a different type of datastore such as VMFS or NFS, register it as a VM and migrate that VM to the vSAN datastore.
This migration converts the file to a vSAN object.

Additional Information

• Unable to upload, copy, or create files in a VMware vSAN-backed datastore
• Flat VMDK on vSAN
• Unable to upload ISO to vSAN datastore from the vCenter web client or ESXi host web client