[SOLVED] Creating or resizing large disk fails - external NFS storage (plenty of space and inodes available...)

Dec 3, 2025
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I'm trying to create a large 6.5TB disk on an external storage device. I've tested creating a dummy file of the same size without issue. However, when creating (or even resizing) a disk of this size I receive the following error. The external storage device is a Dell Powerscale with 500TB free. I can create disks up to 4TB in size without issue.

update VM 987: -virtio0 AgfaVMNFS:6500,format=qcow2,iothread=on
Formatting '/mnt/pve/AgfaVMNFS/images/987/vm-987-disk-0.qcow2', fmt=qcow2 cluster_size=65536 extended_l2=off preallocation=metadata compression_type=zlib size=6979321856000 lazy_refcounts=off refcount_bits=16
qemu-img: Failed to flush the L2 table cache: No space left on device
qemu-img: Failed to flush the refcount block cache: No space left on device
TASK ERROR: unable to create image: qemu-img: /mnt/pve/AgfaVMNFS/images/987/vm-987-disk-0.qcow2: Could not resize image: Allocating clusters failed: No space left on device
 
Hi @greg.amos@capitolimagings, and welcome to the forum.

The error you’re seeing is most likely related to a limitation on the NAS side. The final “no space left” message is essentially a catch-all response, it’s what the client receives when the NAS stops allowing further file creation. Since NFS doesn’t provide a specific error like “file limit reached,” returning an out-of-space condition is the closest match.

A quick search turned up this :
https://www.dell.com/community/en/c...mitations-from-onefs/647f6bb2f4ccf8a8de8d77cc

It would be best to contact your storage vendor (Dell) to confirm whether this limitation still applies in the version of OneFS you’re running. Please let us know what they say - it may help others encountering the same issue.


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
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I've discovered this is a limitation of Dell Powerscale (hard coded 4TiB file size limit)...
Sadly there are still many limits around file management in legacy storage products.

Feel free to mark this thread solved by editing the first post and selecting solved from the dropdown near the subject. This will help keep the forum tidy.

Cheers


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
Unfortunately, this isn't "technically" legacy. This is supposedly a brand new offering, although I'm discovering most of the limitations that were in the old Isolon system are still buried in the Powerscale code. The only one that has had a real impact thus far has been this one however... We got around it by building a NFS export for this data instead of housing it in the VM disk... No single file in our use case will reach 4TiB... Just a strange hard coding to run into for sure... Thanks guys!