请教DS存储中每个HOST使用4块HBA卡的必要性！

Configuration with four HBAs on host and four host ports on DS5000
A configuration with four HBAs and four host ports on DS5000, two on each DS5000
controller is supported with appropriate zoning as shown in Figure 12-11. It is very important
to define two hosts on DS5000 mapping, each defined host residing in a separate host group,
which results in a logical drive being allocated to either one Host Group or the other so is only
accessed by one set of HBAs.
In Figure 12-11, dual HBAs have been used so as to emphasize that if there is adapter failure,
connectivity is not lost to a host group. HBA fcs0 and fcs2 are in one DS5000 Host Group
with fcs1 and fcs3 in the other. If fcs0 and fcs1 were in the same Host Group, then the
physical adapter is a single point of failure and connectivity is lost to that Host Group if the
adapter failed.


每个LUN只能属于其中一个host group，也就只能使用两块HBA卡，那主机使用4块HBA卡的好处就只能是多分担I/O？

Configuration with four HBAs on host and four host ports on DS5000
A configuration with four HBAs and four host ports on DS5000, two on each DS5000
controller is supported with appropriate zoning as shown in Figure 12-11. It is very important
to define two hosts on DS5000 mapping, each defined host residing in a separate host group,
which results in a logical drive being allocated to either one Host Group or the other so is only
accessed by one set of HBAs.
In Figure 12-11, dual HBAs have been used so as to emphasize that if there is adapter failure,
connectivity is not lost to a host group. HBA fcs0 and fcs2 are in one DS5000 Host Group
with fcs1 and fcs3 in the other. If fcs0 and fcs1 were in the same Host Group, then the
physical adapter is a single point of failure and connectivity is lost to that Host Group if the
adapter failed.


每个LUN只能属于其中一个host group，也就只能使用两块HBA卡，那主机使用4块HBA卡的好处就只能是多分担I/O？

Configuration with four HBAs on host and four host ports on DS5000
A configuration with four HBAs and four host ports on DS5000, two on each DS5000
controller is supported with appropriate zoning as shown in Figure 12-11. It is very important
to define two hosts on DS5000 mapping, each defined host residing in a separate host group,
which results in a logical drive being allocated to either one Host Group or the other so is only
accessed by one set of HBAs.
In Figure 12-11, dual HBAs have been used so as to emphasize that if there is adapter failure,
connectivity is not lost to a host group. HBA fcs0 and fcs2 are in one DS5000 Host Group
with fcs1 and fcs3 in the other. If fcs0 and fcs1 were in the same Host Group, then the
physical adapter is a single point of failure and connectivity is lost to that Host Group if the
adapter failed.


每个LUN只能属于其中一个host group，也就只能使用两块HBA卡，那主机使用4块HBA卡的好处就只能是多分担I/O？