Plugin Status [0x8] (THINPROV_NOSPACE: Backing pool for thin-provisioned LUN is out of space) are reported at vmkernel of ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Hosts not responding due to out of space issue with thin-provisioned LUNs.
• VMs may go to a unresponsive state
• Datastore may be in inaccessible state and hence shows '0' bytes as capacity in vCenter UI.
• The commands to the specific datastore\backing LUN may fail with the below-mentioned error in the vmkernel.log file. With time due to this kind of continuous error, the hostd of the hosts accessing this particular datastore will go to a not responding state and the host may get disconnected from vCenter Server.

Note: This error effectively means, the array has put the LUN in read-only mode and all writes are disallowed.

 

[Date]T############# cpu3:2098856)ScsiDeviceIO: 3029: Cmd(0x459a906502c0) 0x2a, CmdSN 0x1a0d2b from world 0 to dev "[Device (naa/eui)]" failed H:0x0 D:0x2 P:0x8 Valid sense data: 0x7 0x27 0x7

 

Plugin Status: [0x8] THINPROV_NOSPACE: Backing pool for thin-provisioned LUN is out of space. 

Sense Key: [0x7] DATA PROTECT
Additional Sense Data: 27/07 SPACE ALLOCATION FAILED WRITE PROTECT

• The I/Os may fail with the below errors as well:

2026-05-20T14:27:42.371Z In(182) vmkernel: cpu22:72009586)Fil6: 4289: 'Datastore_Name': Fil6 file IO (<FD c19 r4>) : No space left on device
2026-05-20T14:27:42.371Z In(182) vmkernel: cpu22:72009586)Fil6: 4251: ioCtx: 0x45ba19b13d00, world: 14724382, overallStatus: No space left on device, token: 0x45d9e9e06640, tokenStatus: Success, txnToken: 0x0, txnTokenStatus: N, totalIOSize: 1048576, maxIOLength: 4609321

 

• I/Os from VMs may fail with the below errors:

2026-06-04T04:47:44.224Z In(182) vmkernel: cpu13:76059676)Fil6: 4251: ioCtx: 0x45ba1a553d80, world: 14724382, overallStatus: No space left on device, token: 0x45d9fc135980, tokenStatus: Success, txnToken: 0x0, txnTokenStatus: N, totalIOSize: 486400, maxIOLength: 39492763
2026-06-04T04:47:44.226Z In(182) vmkernel: cpu13:76059676)Fil6: 4251: ioCtx: 0x45ba1a553d80, world: 14724382, overallStatus: No space left on device, token: 0x45d9fc135980, tokenStatus: Success, txnToken: 0x0, txnTokenStatus: N, totalIOSize: 486400, maxIOLength: 39492763

 

• Specific VMDKs of effected VMs may report the below errors:

2026-06-04T03:15:23.301Z In(05) vmx - [msg.hbacommon.outofspace] There is no more space for virtual disk '/vmfs/volumes/67962cdb-#######-#######-######/VM_Name/VM_Name.vmdk'. You might be able to continue this session by freeing disk space on the relevant volume, and clicking _Retry. Click Cancel to terminate this session

Environment

• VMware vSphere ESXi 8.0.x
• VMware vSphere ESXi 7.0.x

 

Cause

The main cause of this issue is that the LUN backing this datastore is thinly provisioned at the array and the pool where this LUN is part of is out of space and has entered Read-only mode.

Resolution

1. To resolve this issue, the space issue at the array side should be corrected. Make sure that the pool where this LUN is a part is provisioned with more or sufficient free space. For more information, see Thin-provisioned storage devices met soft threshold. 
2. Furthermore, please engage the storage vendor to check the condition of the impacted LUN/pool.

Please Note:

• Within the storage array management interface, thin provisioning allows the array to report actual physical consumption based strictly on written blocks. For instance, if a 300 GB datastore contains 280 GB of written data, the array accurately identifies 280 GB as the physical space used.
• Conversely, vCenter lacks visibility into the LUN pool's physical utilization. It calculates free space by subtracting reported logical usage from the total logical allocation, leading to a consistent disparity between vCenter's available space reports and the array's physical reality.
• Consequently, monitoring datastore free space via vCenter is neither accurate nor efficient when backed by thin-provisioned LUNs.

Additional Information

Japanese Version:
エラー "THINPROV_NOSPACE: Backing pool for thin-provisioned LUN is out of space"