Implementation Guide › Installing a High Availability Deployment › Components of a High Availability Environment › The Shared Storage

The Shared Storage

We recommend that you implement a shared storage solution using shared storage devices. The shared storage must be accessible to both the active and passive servers. Verify that the shared storage solution you use meets the following criteria:

• Write order—the shared storage solution must write data blocks to the shared storage in the same order as they occur in the buffer.
• Synchronous write persistence—upon return from a synchronous write call, the storage solution guarantees that all the data has been written to durable, persistent storage.

The following are examples of the software based shared storage solutions:

• Dual-Port SCSI device
• Storage Area Network (SAN)

Dual-Port SCSI and SAN solutions comply with the write order and synchronous write persistence requirements.