Yes. ZEDEDA/EVE-OS supports attaching a single volume instance to multiple application instances via the multiattach flag combined with the MULTIREAD_SINGLEWRITE access mode. Sharing data between edge apps on the same node is one of the documented primary use cases of the storage feature.

This is a supported, real-world pattern — it is exactly what ZEDEDA's own example_fcm_app_deployment.py SDK example does: one content-tree volume + block-storage volumes with multiattach=True shared across 7 app instances on one node.

The accessmode field accepts these enum values:

To share, use MULTIREAD_SINGLEWRITE and set multiattach = true.

• Same node only. A persistent volume instance belongs to a specific edge node. To share it, every app instance attaching it must run on that same edge node. To have it on another node you must create a separate volume instance there.
• One writer, many readers. MULTIREAD_SINGLEWRITE means the platform lets multiple apps attach, but it does not arbitrate concurrent writers. Two apps mounting the same block device read-write and both writing will corrupt the filesystem (ext4/xfs are not cluster-aware).
• Safe pattern: one app owns writes; the others mount read-only (readonly = true on the drive). If you genuinely need concurrent read-write from multiple apps, do not use block-level multiattach — instead have one app export the data over a network share (NFS / SMB / MinIO) that the others mount.

The zedcloud_volume_instance resource exposes both accessmode and multiattach, so this is done entirely in Terraform.

resource "zedcloud_volume_instance" "shared_persist" {
  device_id   = zedcloud_edgenode.my_edgenode.id
  accessmode  = "VOLUME_INSTANCE_ACCESS_MODE_MULTIREAD_SINGLEWRITE"
  multiattach = true
  cleartext   = false
  label       = "shared-persist"
  name        = "shared-persist"
  size_bytes  = 1073741824
  title       = "shared-persist"
  type        = "VOLUME_INSTANCE_TYPE_BLOCKSTORAGE"
  lifecycle {
    ignore_changes = [device_id]
  }
}

  drives {
    imagename   = ""
    volumelabel = zedcloud_volume_instance.shared_persist.label
    mountpath   = "/data"
    cleartext   = false
    ignorepurge = true
    maxsize     = 1073741824
    preserve    = true
    target      = "Disk"
    drvtype     = "HDD"
    readonly    = false   ### writer
  }

  drives {
    imagename   = ""
    volumelabel = zedcloud_volume_instance.shared_persist.label
    mountpath   = "/data"
    cleartext   = false
    ignorepurge = true
    maxsize     = 1073741824
    preserve    = true
    target      = "Disk"
    drvtype     = "HDD"
    readonly    = true    ### reader
  }

Referencing the same volume from two app instances while the volume is still defined as plain VOLUME_INSTANCE_ACCESS_MODE_READWRITE with no multiattach is not a valid shared config — it either fails to attach to the second app or produces two uncoordinated read-write mounts. Always set multiattach = true + MULTIREAD_SINGLEWRITE, and keep only one writer.

• Sharing a persistent volume across apps is supported — multiattach = true + MULTIREAD_SINGLEWRITE.
• Same edge node for all attaching apps.
• One writer, others read-only; for concurrent multi-writer, use a network share instead.
• Fully configurable in the zedcloud Terraform provider (accessmode, multiattach, per-drive readonly).