Avanti supports shared disks for clustering, where several nodes share one or more disk drives.  Disk sharing between Avanti instances running on the same host system is enabled using the write_share option in the advance disk options (see SCSI Disk [+]).

Warning:Using the write_share feature to share disks with non-clustered Avanti instances is not recommended.  Doing so may result in disk corruption.

If Avanti is running on separate host systems, disk sharing is only possible using physical devices such as SAN disks that are physically shared between the host systems.

To enable disk sharing, point each Avanti configuration file at the exact same disk image file(s) and enable write_share for each shared disk.

 

Example: An OpenVMS 8.3 cluster shares a system disk and quorum disk.  The disks are store in image files VMS83_Clustering.img and V83_Quorum.img.  This image depicts the use of the write_share option to enable disk sharing between Avanti instances.  It also depicts the TCQ option required on the quorum disk.  Each disk definition in the other cluster member Avanti configuration files is tagged with the write_share option.  All configuration files point at the same disk image files.