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Note – You cannot use all disks for data when using 108 146-Gbyte or 72 250-Gbyte
disks. The remaining disks are usually used as spares.
Be sure to check the latest product Release Notes for additional guidelines or
limitations for large configurations.
Each LD can be partitioned into up to 128 separate partitions or used as a single
partition. Partitions are presented to hosts as LUNs.
Once the LDs have been created, assigned to a controller, and partitioned, the
partitions must be mapped to host channels as LUNs in order for them to be seen by
a host. It is usually desirable to map each partition to two host channels for
redundant pathing.
A partition can only be mapped to a host channel where its controller has an
assigned ID. For example, if LD 0 is assigned to the primary controller, all partitions
on LD 0 will need to be mapped to a host channel ID on the primary controller
(PID). Any LDs assigned to the secondary controller will need to have all partitions
mapped to a host channel ID on the secondary controller (SID).
When attaching FC cables for LUNs configured with redundant paths, make sure
one cable is connected to a channel on the upper controller and the other cable is
connected to a different channel on the lower controller. Then, if multipathing
software is configured on the host, a controller can be hot-swapped in the event of
failure without losing access to the LUN.
For example, suppose partition 0 of LD0 is mapped to Channel 0 PID 42 and
Channel 5 PID 47. To ensure that there is no single point of failure (SPOF), connect a
cable from the host HBA or a switch port to the upper board port FC0, and connect
a second cable from the lower board port FC5 to a different host HBA or switch.
Cache Optimization
The Sun StorEdge 3500 series provides settings for both sequential I/O and random
I/O. Sequential I/O is the default setting. As previously discussed, the StorEdge
3511 SATA array provides a subset of the StorEdge 3510's function. Given the
characteristics of SATA disks and the application performance requirements for bulk
storage, the StorEdge 3511 SATA array should never be used with the random I/O
setting. Poor performance and loss of data availability may occur. Sequential I/O is
the default setting. See
for a brief overview of the optimization modes.
TABLE 6
The logical drive, cache memory, and other controller internal parameters are
adjusted to transfer information most efficiently for each optimization mode; they
also control the size of logical drives and number of disks per logical drive. For the
maximum capacity and number of disks in each optimization mode, refer to:
Best Practices for the Sun StorEdge 3510 and 3511 FC Arrays
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