Skip to content

Sharing Disks Between Virtual Machines#

Overview#

VergeOS does not currently attach a single block device to multiple running VMs at the same time. When we need to share data across VMs today, we have two supported approaches: duplicate the disk (Clone Disk) so each VM gets its own independent copy, or share a file system over the network by mounting a NAS share from each guest. This page explains what each method does, when to choose it, and where to find the procedure.

What You'll Learn#

  • The difference between Clone Disk and NAS-based file sharing
  • When to use each method based on your use case

What You'll Need#

  • A running VergeOS environment with at least two virtual machines
  • Administrative access to the VergeOS UI
  • For NAS shares: a configured NAS service

Comparison#

Method What it shares Read/Write semantics Best for Limitations
Clone Disk An independent copy of an existing .raw disk, made at drive-creation time Each VM owns a private read/write copy. Changes are not synchronized back to the source or to other clones. Seeding new VMs from a known-good disk image, handing off a point-in-time dataset to another VM One-time copy only — not a live sharing mechanism. Clones diverge from the source the moment they are created. Permissions are inherited from the source disk.
NAS share (SMB/NFS) A NAS volume exposed as a network share and mounted by multiple guests Concurrent read/write at the file level, mediated by the NAS service and the share protocol Shared application data, file repositories, content libraries, and any workflow where multiple VMs need to read or write the same files File-level only, not block-level. Network overhead compared to local disk I/O. Concurrency, locking, and performance depend on the protocol and the guest OS. Granular share-level and filesystem-level permissions are available.

Method 1 — Clone Disk#

A Clone Disk is a point-in-time copy of an existing .raw drive (the default format for VergeOS VM disks) in the same VergeOS cloud. It is created when we add a drive to a VM and select Clone Disk as the media type. Once created, the clone is fully independent of the source: writes from the cloned VM stay in the clone, and writes to the source are not visible to the clone. Because the clone is a full copy, it is unaffected if the source drive is later modified or deleted. This is the right choice for initializing a VM from an existing disk, not for keeping data in sync between VMs.

For the step-by-step procedure, see Virtual Machine Drives and select Clone Disk at the Media step.

Method 2 — NAS Share#

A NAS share is a volume hosted by the VergeOS NAS service and exposed over SMB or NFS. Each VM mounts the share like any other network file system, and the NAS coordinates concurrent access across all connected guests. This is the supported way to give multiple VMs simultaneous read/write access to the same data.

For setup, see the NAS Overview and NAS Shares.

Choosing Between Them#

  • Use Clone Disk when we need a new VM to start with a copy of an existing disk and then evolve independently — for example, deploying several VMs from the same prepared OS or data disk.
  • Use Clone Disk for a one-time data hand-off where the receiving VM should own its copy.
  • Use a NAS share when two or more VMs need to read or write the same files concurrently.
  • Use a NAS share for shared application content, team file storage, build artifacts, media libraries, or any workflow where consistency across VMs matters.
  • Do not use Clone Disk to keep data in sync between VMs — clones diverge immediately and there is no merge-back.

Roadmap

Simultaneous multi-VM attach of a single drive — both read-only and read/write — is planned for a future VergeOS release. This page will be updated when that capability is available.

Summary#

In short: Clone Disk for seeding, NAS for sharing. We covered the two supported methods for sharing data between virtual machines in VergeOS:

  • Clone Disk for creating independent, point-in-time copies of an existing drive — local block-level I/O, no network overhead, but no synchronization
  • NAS shares for concurrent, file-level access from multiple VMs over SMB or NFS — with granular access control and live collaboration, at the cost of network overhead

Next Steps#