Creating or expanding a file in VMFS-5 fails with error: "no more space"

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
Creating or expanding a file in VMFS-5 fails with error no more space even if VMFS-5 volume is not full.

Environment

VMware vSphere ESXi 6.5

Cause

When a file size is more than 256MB, Pointer Block is consumed.

Note: 1 Pointer Block per 1 GB

If Pointer Blocks are exhausted, no more space error might occur.

Maximum number of Pointer Blocks is usually 64512 and not configurable.

Number of Pointer Blocks is found with vmkfstools.
 

For Example:

Used of Pointer Blocks is 30018.
Free of Pointer Blocks is 34494.

# vmkfstools -P -v10 /vmfs/volumes/testvol
VMFS-5.81 (Raw Major Version: 14) file system spanning 1 partitions.
File system label (if any): testvol
Mode: public
Capacity 10994847842304 (10485504 file blocks * 1048576), 2908706832384 (2773959 blocks) avail, max supported file size 69201586814976
Volume Creation Time: Fri Dec  1 07:32:45 2017
Files (max/free): 130000/69985
Ptr Blocks (max/free): 64512/34494                        <----
Sub Blocks (max/free): 32000/32000
Secondary Ptr Blocks (max/free): 256/256
File Blocks (overcommit/used/overcommit %): 0/7711545/0
Ptr Blocks  (overcommit/used/overcommit %): 0/30018/0     <----
Sub Blocks  (overcommit/used/overcommit %): 0/0/0
:
#

Resolution

This is a limitation with VMFS 5.

Workaround:
To workaround this issue, delete unused files.