Accusys ExaRAID GUI - Manual (Page 271)

Appendix
B-2
Selective presentation for sophisticated storage area network (SAN)
environments
The administrators can choose an appropriate presentation method
according to the environment to quickly complete the presentation at the
deployment stage and effectively manage the presentation at the
maintenance stage.
• Host and LUN management
The host HBA ports are managed by groups and the internal storage
resources are exported as LUNs managed in distinct storage groups.
Because the storage presentation can be conducted based on the groups,
the presentation process can be simplified and more easily managed.
• Independent LUN attributes
Each LUN can have different attributes, such as CHS geometry, sector size,
and optimization policy. All LUNs can be independently and dynamically
masked or unmasked. IO access control of LUN can be also enforced for
security or for isolating problematic host computers. Because each LUN can
be independently configured, storage resources can be virtualized and
shared without unnecessary compromise.
B.3 Flexible Storage Provisioning
Storage provisioning is the process to organize the physical disks with
appropriate RAID configurations, which determine the level of performance
and reliability of LUNs. The more RAID configurations a storage system can
provide the more types of applications that the system can serve. The RAID
controller firmware supports versatile RAID configurations as well as flexible
storage provisioning that can achieve high utilization of disk space and
enable sharing storage resources.
• Comprehensive RAID configurations
To fulfill different requirements, a variety of RAID configurations are offered:
Multiple disk groups (multiple array)
Multiple logical disks per disk group (support RAID partitioning)
Variable RAID levels supported
Variable stripe sizes supported
Hot spare with both global spare and local spare
Support auto-spare option for data rebuilding on unused disks
• Multiple RAID configurations on single disk group
Contrary to legacy RAID partitioning, by which all logical disks are merely
partitions of a disk group and they have the same RAID configurations, the
firmware offers flexible storage presentation, where multiple RAID levels and