"Issue of delete blocks failed" error is displayed in vmkernel.log file

Products

• VMware vSphere ESXi

Issue/Introduction

The purpose of this article is to fix the memory leak issue which can occur when the below error message is logged repeatedly.
FSDisk: 260: Issue of delete blocks failed [sync:0] numDescs 1 Address is not aligned on required boundary 0x439dc0c5cb40.

Symptoms:

• In the /var/log/vmkernel.log file, you see entries similar to:
  
  FSDisk: 260: Issue of delete blocks failed [sync:0] numDescs 1 Address is not aligned on required boundary
  0x439dc0c5cb40

​​

• hostd and/or vpxa process gets crashed due to random crypt failure.​

Environment

VMware vSphere ESXi 5.5
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Embedded
VMware ESXi 4.0.x Installable
VMware vSphere ESXi 5.0
VMware ESXi 4.0.x Embedded
VMware vSphere ESXi 5.1
VMware vSphere ESXi 6.0
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 6.5

Cause

In the situation, Issue of delete blocks failed message is logged, ESXi can keep small memory data which should be released although this message itself is an informative and harmless. After a lot of this situation repeated, ESXi can exhaust a slab which is used to provide this memory data and it raises hostd/vpxa crash.

Resolution

This issue is resolved in,

• VMware ESXi 6.0 Patch 05, available at VMware Downloads.
• VMware ESXi 6.5 Update 1, available at VMware Downloads.

Workaround:

This can happen with RDM/VMFS backed LUNs. But if virtual RDM devices are configured, use one of these options:

• Use physical RDM instead of virtual RDM to the virtual machines.
• Disable the UNMAP commands from the guest operating system.

Note: UNMAP commands issued from the guest operating system are now supported on vSphere 6.

Additional Information

 

Thin Provisioning Block Space Reclamation (VAAI UNMAP) does not work
「Issue of delete blocks failed」エラーが vmkernel.log ファイルに表示される
在 vmkernel.log 文件中显示 “Issue of delete blocks failed” 错误