System information

Appendix
B-2
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 stripe sizes can
coexist in single disk group. This largely improves the utilization of disk space as well as simplifies the configuration planning.
• Online volume management
The firmware provides online volume management to build LUNs of multi-level RAID by striping over two or more logical
disks for higher performance (aggregating horsepower of more disks), better reliability (multiple independent parity), and
larger capacity (distributing data over more disks). To further utilize the disk space, a capacity-oriented volume can be
created by concatenating multiple logical disks of different capacity to form storage with huge capacity. Without the
embedded volume management, the administrator is required to use different host-based volume management software for
different operating systems, which results in difficulties in managing volume configurations and risks of configuration lost if
there is anything wrong with the host computers.
• RAID quick setup
Within very few steps, the administrator can complete the RAID configurations for all disks as well as basic system settings.
The RAID quick setup is provided through multiple user interfaces: Web GUI, CLI, and LCD. By the RAID quick setup, a
reliable storage system can quickly be available within only a few minutes, needing no sophisticated expertise.
B.4 Comprehensive RAID Configurations
RAID (Redundant Array of Independent Disks) technologies are deemed as the most promising solutions for building disk-
based massive storage systems with high performance and reliability. The RAID controller firmware provides comprehensive
RAID levels and stripe sizes such that a storage system can fulfill different types of requirements. In addition, valuable
enhancements are also provided to offer useful flexibilities. Combining with flexible storage provisioning and presentation, the
firmware can unleash the power of the controller and meet users’ needs.
• Comprehensive RAID levels
The firmware supports a variety of RAID levels: RAID 0, 1, 3, 5, 6, 10, 30, 50, 60, NAND, and JBOD. You may freely choose
the RAID levels that fit your applications well with a balanced set of performance, capacity, and reliability.
• Selective stripe sizes
The firmware supports stripe sizes of 4KB, 8KB, 16KB, 32KB, 64KB, 128KB, 256KB, and 512KB. To serve small-sized
access, smaller stripe sizes are advised to shorten the response time and increase the number of accesses processed. On
the other hand, for bulky-data access, bigger stripe sizes are advised to improve the throughput.
• Selective initialization method and mode
To initialize a logical disk, either data zeroing or background parity regeneration can be used. The administrator can choose
to execute the background initialization for all logical disks simultaneously or one by one sequentially. To avoid confusing the
operating systems, the background initialization will also clean up the data on the first few sectors to erase the file system
super blocks. To speed up the initialization, the administrator can also choose to initialize the disk group and skip the
initialization of logical disks.
• Selective rebuild mode
The rebuild mode of a disk group determines the rebuilding order of logical disks on the disk group. Three rebuild modes are
available: parallel, sequential, and prioritized, by which the rebuilding will be done simultaneously for all logical disks,
sequentially from the first to the last logical disks, and sequentially according to the order specified by the administrator,
respectively.