Creating 3-Copy Virtual Disks
3-copy virtual disks can be created in the following ways:
- Host context: Use the Create Virtual Disk operation to create and serve a virtual disk with a redundancy level of three. This creates three data copies of the virtual disk. See Quickly Creating and Serving Virtual Disks for instructions.
- Create Virtual Disk wizard: Use the wizard to create a mirrored virtual disk, with 2 data copies, and add another mirror. See Creating a Virtual Disk from the Wizard and Adding Mirrors for instructions.
- Create Another operation: Use this operation to create more virtual disks using a 3-copy virtual disk as the basis. See Creating Virtual Disks Using Another as a Model for instructions.
Storage Sources
A 3-copy virtual disk has three storage sources:
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Parent - Host Access = Read/WriteMirror
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Host Access = Read/WriteChild
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Host Access = Not Allowed
The virtual disk will appear in the DataCore Servers panel under each server that is included as a storage source. Storage source details are displayed in the Virtual Disk Details page under the Info tab and in the Virtual Disks list under the Virtual Disk Summary. When the parent or mirror storage source is offline, and demoted to being the child source by automatic self-healing, it will remain as a child even when brought back online.
- A multi-copy virtual disk has front-end paths between the host and all storage sources. However, host access is available to no more than two DataCore Servers at a time. Storage sources that are accessible to the host or are capable of being accessible to the host (if not served) are considered "active" storage sources. The storage source that has host access disabled is considered an "inactive" storage source. Host access may change among the storage sources in the virtual disk to maintain high availability as various failure conditions or operations are handled.
- Automatic self-healing is enabled by default. See Automatic Self-Healing for more information.
- All storage sources in a multi-copy virtual disk are displayed in the Virtual Disk Details page>Info tab and in the Summary when the virtual disk is selected in the Virtual Disk List.
- A Shared Multi-port Array license is not required for dynamic data resiliency, nor are shared pools. Dynamic data resiliency is not supported for dual virtual disks.