This section contains guidelines for properly placing and connecting the disk shelves.
For safety reasons, mount the heaviest equipment, typically disk shelves, at the bottom of the cabinet. Refer to the appropriate Oracle Safety and Compliance Guide for rack-mounting guidelines.
To best prepare for cabling controllers to disk shelves, now and in the future, mount controllers in the middle of the cabinet. This also allows for optimal air circulation, whether in a floor- or ceiling-cooled environment.
Do not remove cabinet panels to run cables between cabinets.
Balance the number of disk shelves across the disk chains in your system.
Balance the number of disk chains across the number of HBAs in your system. For example, attaching two chains to two separate HBAs will have better performance than attaching two chains to a single HBA.
Do not mix disks with different capacities or rotation speeds within a single disk shelf.
To maximize performance, use the maximum number of disk chains supported by the controller's SAS HBAs. For example, four SAS HBAs with eight chains and eight disk shelves will have better performance than two SAS HBAs with four chains and eight disk shelves.
To maximize performance, do not attach more than four DE2-24C, DE2-24P, or DE3-24C disk shelves to a single chain, and do not attach more than three DE3-24P disk shelves to a single chain. This only applies to systems that are performance critical. The maximum of six disk shelves per chain is available for cases where capacity is preferred over performance.
Active optical cables (AOCs) are required for attaching ZS7-2 controllers to DE3-24 disk shelves. Other controllers and/or disk shelves in the future may adapt AOC cabling. AOCs are available in the following lengths: 3 meters, 6 meters, and 20 meters. The maximum AOC length between a controller and disk shelves that span further than two adjacent cabinets is 20 meters.
The maximum copper cable length between a controller and disk shelves is 6 meters.
The maximum copper or AOC cable length between DE3-24 disk shelves in a single chain that spans two adjacent cabinets is 6 meters copper, 6 meters AOC, or 20 meters AOC; only one pair of 6-meter cables is allowed per chain.
The maximum copper cable length between DE3-24 disk shelves that span across adjacent cabinets is 3 meters.
The maximum copper cable length between DE2-24 disk shelves that span across adjacent cabinets is 3 meters.
The maximum copper cable length between Sun Disk Shelves that span across adjacent cabinets is 3 meters.
Do not bend SAS cables less than the following minimum radius:
|
Disk shelves are supported by specific HBAs in the controller, and can be combined in certain configurations within a system. Use the following table to determine the HBA type required by each disk shelf model.
|
The following table describes which disk shelf models can be used together for which controller configurations, starting with software release OS8.7.0. See Cabinet and Cabling Guidelines in Oracle ZFS Storage Appliance Cabling Guide for disk shelf intermixing guidelines and all-flash disk shelf usage. To understand which controllers support which HBA types, see Maximum Disk Shelves per Controller Configuration.
|