Configuring virtual SCSI HBAs and virtual SANs is very flexible. The physical SCSI HBA initiator port that is used by the ldm add-vsan command can drive any type of bus that supports SCSI, such as Fibre Channel, SAS, or SATA. The virtual SCSI HBA and virtual SAN can execute in the same domain. Also, a virtual SAN can execute in an I/O domain after using the ldm add-io command to add a physical SCSI HBA card to a service domain.
Although a virtual SAN is conceptually associated with a physical SAN, it does not need to be. You can create a virtual SAN that comprises one or more of a server's local disks. For example, some systems have disks that are reachable from the motherboard's SAS HBA, which is shown as SASHBA in the following ldm list-hba output:
primary# ldm list-hba -d primary
NAME MY_VSAN
---- ----
/SYS/MB/SASHBA0/HBA0/PORT4
c5t5000CCA0564DEF39d0s0
/SYS/MB/SASHBA0/HBA0/PORT1
c3t5000CCA0564F1A7Dd0s0
/SYS/MB/SASHBA0/HBA0/PORT2
c4t5000CCA0564F6B89d0s0
/SYS/MB/SASHBA0/HBA0/PORT8
c6t5000CCA0564FCF6Dd0s0
If you define a virtual SAN that encapsulates a server's local disks, be sure to use the following zpool command so that you do not mistakenly create a virtual LUN for the disk from which the primary domain boots. For example, the following zpool command confirms that the root rpool is mounted on disk c4t5000CCA0564F6B89d0, which is reachable from the /SYS/MB/SASHBA0/HBA/PORT2 initiator port:
# zpool iostat -v
capacity operations bandwidth
pool alloc free read write read write
----------------------- ----- ----- ----- ----- ----- -----
rpool 25.0G 531G 0 10 257 81.7K
c4t5000CCA0564F6B89d0 25.0G 531G 0 10 257 81.7K
----------------------- ----- ----- ----- ----- ----- -----
When configuring a virtual SAN, note that only SCSI target devices with a LUN 0 have their physical LUNs visible in the guest domain. This constraint is imposed by an Oracle Solaris OS implementation that requires a target's LUN 0 to respond to the SCSI REPORT LUNS command.