NFS Datastore Failed SVMFDSIoctlMoveData: No space left on device
Article ID: 378036
Updated On: 03-10-2025
Products
Issue/Introduction
- Datastore shows free space available via the vCenter client
- VMs give the error "There is no more space for virtual disk"
- Unable to migrate VMs to another datastore
VMkernel.log shows:
[YYYY-MM-DDTHH:MM:SS] cpu50:2204508)WARNING: SVM: 2869: scsi0:0 Failed SVMFDSIoctlMoveData: No space left on device
[YYYY-MM-DDTHH:MM:SS] cpu15:2206080)VmfsSparse: 6482: fd 16468308: Setting freeSector as 98819312. bad REs 0 bad LEs 0 maxSector 98819312 endOfRETable 444 nonEmptyREs 25379 emptyLEs 0 numREs 56320 prevAllocSectors 98730432 allocSectors 98828736
[YYYY-MM-DDTHH:MM:SS] cpu15:2206080)Cow: 1991: Sync IO issued on cow disk 'testmachine.vmdk' failed with No space left on device
[YYYY-MM-DDTHH:MM:SS] cpu15:2206080)VmfsSparse: 2062: Sparse COW open (fd 16468308, isSparse: 0, sparseInfo 0x43125fe01ba0) finished with status: No space left on device
[YYYY-MM-DDTHH:MM:SS] cpu15:2206080)Cow: 612: Failed to open file testmachine.vmdk, level 1 of 2 (extent 'vmfssparse' fhID16468308) with No space left on device
[YYYY-MM-DDTHH:MM:SS] cpu15:2206080)WARNING: DD: 630: Opening the cow hierarchy for testmachine.vmdk failed with No space left on device
Environment
VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x
Cause
The error message indicates that a Storage Virtualization Manager (SVM) failed to move data due to insufficient storage space on the device. This error often occurs when a virtual machine needs to write to disk and there is not enough space available on the underlying storage.
Resolution
1. Regularly monitor the storage usage of datastores and VMs to identify potential space issues early.
2. As a best practice, delete old snapshots to reclaim space.
3. Check the NFS server's logs for any error messages or indications of problems.
4. Problems with the NFS server, such as hardware failures or software issues, that can affect data availability and storage space.
Additional Information
The Network File System (NFS) server is the machine that shares files and directories over a network. It's where the actual data for the COW disk is stored.
COW Disk (Copy-on-Write Disk): A copy-on-write disk is a type of virtual disk where changes are written to a separate delta file. This helps improve performance and reduces the amount of data that needs to be transferred over the network.
NFS storage: Using NFS storage for COW disks can provide benefits such as centralized management, scalability, and high availability.
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