This topic provides rules and examples of a configuration
that uses a three-way split backplane.
The following rules apply
to this configuration:
- A three-way split backplane uses three sets of two drives and
cannot function in dual storage I/O adapter (IOA) or high availability
(HA) RAID mode. One SAS adapter connects to D1 and D4. The other SAS
adapter connects to D2 and D5. An external SAS adapter connects to
D3 and D6.
- The SAS adapters can be assigned to separate partitions for boot
devices.
- This configuration supports disks without RAID (referred to as
JBOD) or RAID drives. However, RAID drives are limited to two drives
and no write cache.
- RAID 10 with two drives is limited. A RAID 10 array with two drives
is equivalent to RAID 1 (mirrored drives). A RAID 0 disk array with
one drive is similar to JBOD support. A RAID 10 array with one drive
is not allowed.
- Solid-state drives (SSDs) and hard disk drives (HDDs) can never
be mixed in the same disk enclosure.
- SSD and HDD can both be present in a split backplane if each side
of the split backplane has only SSD or HDD.
Example: Three-way split backplane
This
example shows a three-way split backplane configuration. Each embedded
SAS adapter controls two disk drives, and the SAS adapter that is
connected to the internal cable controls two disk drives.
Figure 1. Disk
bays controlled by each embedded SAS adapter in a three-way split
backplane
Figure 2. Physical connection to internal SAS adapter
The following table lists the details of the three-way split
backplane configuration.
Table 1. Configuration
detailsEmbedded SAS adapter |
Configuration details |
Embedded SAS adapter A |
- The SAS adapter connects to disk drive D1 and D4.
- The SAS adapter reports CCIN 57C7.
|
Embedded SAS adapter B |
- The SAS adapter connects to disk drive D2 and D5.
- The SAS adapter reports CCIN 57C7.
|
SAS adapter (FC 5901) |
- The physical connections to the internal SAS cable are enabled.
The SAS adapter that is connected to this cable connects to disk drive
D3 and D6.
- The SAS adapter reports CCIN 57B3.
|