We have been building and even doing our performance/benchmarks tests on the ESX 3.x and Oracle RAC. And Sun folks too want to demo their cool software on ESX.
However, VMware ESX has a feature called Raw Device Mapping (RDM), which allows the guest operating systems to have direct access to the devices, bypassing the VMware layer. More information on RDM can be found in VMware documentation. The following documents could be starting points:
http://www.vmware.com/pdf/vi3_301_201_intro_vi.pdf
http://www.vmware.com/pdf/vi3_301_201_san_cfg.pdf
RDM works with either Fibre Channel or iSCSI only. In the setup here, a SAN storage box connected through Fibre Channel was used for mapping LUNS to the physical hosts. These LUNS could then be mapped onto the VMware guests using RDM. SCSI reservations have been found to be working fine with RDM (both SCSI-2 Reserve/Release and SCSI-3). These RDM devices could therefore be used as shared devices between the cluster nodes. However, of course they can also serve as local devices for a node.
One point to note here is that the virtual SCSI controllers for the guest OSes need to be different for the local and the shared disks. This is a VMware requirement when sharing disks. Also the compatibility mode for RDM, to allow direct access to the storage from the guest, should be “Physical”. For detailed information, please refer to VMware ESX documentation.
Decent article, check it out.
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