1. Oracle ZFS Storage Appliance Cabling Guide, Release OS8.8.x
  2. Getting Started with Cabling
  3. Cabinet and Cabling Guidelines

Cabinet and Cabling Guidelines

This section contains guidelines for properly placing and connecting the Oracle disk shelves.

Cabinet Configuration

  • 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.

Load Distribution

  • 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 across two separate HBAs will have better performance than attaching two chains to a single HBA.

  • Do not mix disks with different rotational 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 Oracle Storage Drive Enclosure DE2-24C, DE2-24P, or DE3-24C disk shelves to a single chain or eight Oracle Storage Drive Enclosure DE3-12C disk shelves to a single chain, and do not attach more than three Oracle Storage Drive Enclosure DE3-24P disk shelves to a single chain. This only applies to systems that are performance critical. The maximum of 6 Oracle Storage Drive Enclosure DE3-24/DE2-24 disk shelves or 12 Oracle Storage Drive Enclosure DE3-12C disk shelves per chain is available for cases where capacity is preferred over performance.

HBA Support for Disk Shelves

Disk shelves may require adding or replacing HBAs in your configuration. For HBA maintenance procedures for each controller, see Oracle ZFS Storage Appliance Customer Service Manual, Release OS8.8.x.

  • A SAS-2 HBA always operates at SAS-2 interface speeds, whether it is directly attached to Oracle Storage Drive Enclosure DE2-24 or DE3-24 disk shelves, or whether the disk chain includes all Oracle Storage Drive Enclosure DE2-24, all Oracle Storage Drive Enclosure DE3-24, or an intermix of Oracle Storage Drive Enclosure DE2-24 and DE3-24 disk shelves.

  • A SAS-3 HBA always operates at SAS-2 interface speeds if directly attached to an Oracle Storage Drive Enclosure DE2-24 disk shelf.

  • A SAS-3 HBA always operates at SAS-3 interface speeds if directly attached to an Oracle Storage Drive Enclosure DE3-24/DE3-12 disk shelf, or when the disk chain comprises all Oracle Storage Drive Enclosure DE3-24/DE3-12 disk shelves.

  • Aggregate bandwidth should be based on SAS-2 interface speeds when mixing Oracle Storage Drive Enclosure DE2-24 and DE3-24 disk shelves in a disk chain connected to a SAS-3 HBA.

Cable Lengths

  • Active optical cables (AOCs) are required for attaching Oracle ZFS Storage ZS7-2 controllers to Oracle Storage Drive Enclosure DE3-24 disk shelves, or attaching Oracle ZFS Storage ZS9-2 controllers to Oracle Storage Drive Enclosure DE3-24 or Oracle Storage Drive Enclosure DE3-12C disk shelves. Other controllers and/or disk shelves in the future might use 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.

  • Oracle Storage Drive Enclosure DE2-24 disk shelves with specific drive types (see Cabling Mixed Oracle Storage Drive Enclosure DE3-24 and DE2-24 Disk Shelves to Oracle ZFS Storage ZS9-2 High-end (HE) Controllers) are supported by Oracle ZFS Storage ZS9-2 controllers and require connections with copper SAS cables. Oracle Storage Drive Enclosure DE2-24 disk shelf connection to Oracle ZFS Storage ZS7-2 controllers is supported in software release OS8.8.4 and later. Available copper cable lengths between the Oracle ZFS Storage ZS9-2 or ZS7-2 controller and the Oracle Storage Drive Enclosure DE2-24 disk shelf are 3 meters and 6 meters.

  • The maximum copper cable length between a controller and disk shelves is 6 meters.

  • The maximum copper or AOC cable length between Oracle Storage Drive Enclosure DE3-24 or Oracle Storage Drive Enclosure DE3-12C disk shelves in a single chain that spans two adjacent cabinets is 6 meters copper or 20 meters AOC; only one pair of 6-meter or 20-meter cables is allowed per chain.

  • The maximum copper cable length between Oracle Storage Drive Enclosure 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.

For further guidelines for cabling together disk shelves, see Cabling Disk Shelves Together.

Cable Bend Radius

Do not bend SAS cables less than the following minimum radius:

SAS Cable Type SAS Cable Length Minimum Bend Radius

Copper

1 meter

26 mm

Copper

3 meters

28 mm

Copper

6 meters

35 mm

Active Optic Cable

All lengths

25 mm

All-Flash Disk Shelves

Oracle Storage Drive Enclosure all-flash disk shelves contain only SSDs, and utilize all-flash pools (AFP). To maximize performance, observe the following guidelines:

  • To maximize performance, connect a maximum of two all-flash disk shelves in a single chain.

  • Spread disk chains across as many SAS-3 HBAs as allowed by the system.

  • To maximize performance, segregate all-flash disk chains from non-all-flash disk chains. For example, do not mix all-flash Oracle Storage Drive Enclosure DE3-24P disk shelves in a chain with Oracle Storage Drive Enclosure DE3-24C/DE3-12C disk shelves.

  • Only connect all-flash disk shelves to a SAS-3 HBA in the controller, and use SAS-3 qualified cabling (do not use SAS-2 cabling).

Disk Shelf Installation and Upgrade Considerations

  • Installing a new system - To maximize performance, avoid intermixing Oracle Storage Drive Enclosure DE3-24/DE3-12 and Oracle Storage Drive Enclosure DE2-24 disk shelves when installing a new system. Exclusively use a SAS-3 HBA, Oracle Storage Drive Enclosure DE3-24/DE3-12 disk shelves, and associated SAS-3 cabling to take advantage of the high performance SAS-3 fabric.

  • Upgrading a system - When upgrading a system, choose the mixture of disk shelves according to your storage needs:

    • Upgrading an obsolete component - Replace the obsolete component and its associated components, which could be the SAS HBA, or disk shelf, and respective cabling. When possible for your system, add SAS-3 fabric components.

    • Segregating the upgrade for increased performance - If a controller has empty HBA slots, add SAS-3 HBAs (if supported by the controller model), DE3-24 disk shelves, and associated cabling.

    • Maximizing performance - Upgrade all components, possibly including controllers, to support an all DE3-24 disk shelf configuration with SAS-3 HBAs in the controller, and appropriate cabling.

Maximizing Performance with Intermixed DEx-24/DE3-12 Disk Shelves

To maximize performance when mixing Oracle Storage Drive Enclosure DE3-24/DE3-12 and DE2-24 disk shelves, observe the following guidelines:

  • A disk chain should ideally contain only Oracle Storage Drive Enclosure DE3-24/DE3-12 or DE2-24 disk shelves. Note that Oracle Storage Drive Enclosure DE3-12C disk shelves are not supported in chains with Oracle Storage Drive Enclosure DE2-24 disk shelves.

  • Attach SAS-3 HBAs to Oracle Storage Drive Enclosure DE3-24/DE3-12 disk shelves, and attach SAS-2 HBAs to Oracle Storage Drive Enclosure DE2-24 disk shelves. Note that Oracle Storage Drive Enclosure DE3-12C disk shelves are not supported in chains with Oracle Storage Drive Enclosure DE2-24 disk shelves.

Cabling for Intermixed Oracle Storage Drive Enclosure DEx-24/DE3-12 Disk Shelves

  • Disk Chain Cables - Oracle Storage Drive Enclosure DE2-24 and DE3-24 disk shelves require different cable connectors. Select the correct cables according to the disk shelves being connected:

    • Oracle Storage Drive Enclosure DE2-24 to DE2-24 disk shelf: SFF-8088 connectors on both cable ends

    • Oracle Storage Drive Enclosure DE3-24/DE3-12 to DE3-24/DE3-12 disk shelf: SFF-8644 connectors on both cable ends

      Note that Oracle Storage Drive Enclosure DE3-12C disk shelves are not supported in chains with Oracle Storage Drive Enclosure DE2-24 disk shelves.

    • Oracle Storage Drive Enclosure DE2-24 to DE3-24 disk shelf: SFF-8088 connector on Oracle Storage Drive Enclosure DE2-24 cable end, SFF-8644 connector on Oracle Storage Drive Enclosure DE3-24 cable end

  • HBA Cables - The different disk shelf types require different cables for connecting to a SAS-3 or SAS-2 HBA. Select the correct cables according to the disk shelves being connected:

    • SAS-3/SAS-2 HBA to Oracle Storage Drive Enclosure DE3-24 disk shelf: SFF-8644 connectors on both cable ends

    • SAS-3 HBA to Oracle Storage Drive Enclosure DE3-12C disk shelf: SFF-8644 connectors on both cable ends

    • SAS-3/SAS-2 HBA to Oracle Storage Drive Enclosure DE2-24 disk shelf: SFF-8644 connectors on HBA cable end, and SFF-8088 connector on disk shelf end

Intermixing Oracle Storage Drive Enclosure DE2-24 and Sun Disk Shelves

  • For controllers that support using Oracle Storage Drive Enclosure DE2-24 and Sun Disk Shelves together, the controller must use 4X4 port SAS-2 HBAs, which are supported as of software release 2013.1.0.

  • Do not use Oracle Storage Drive Enclosure DE2-24 and Sun Disk Shelves in the same disk chain.