Because of the unique architecture of blade servers, there are a number of important things to keep in mind when configuring your disk sub-system. These include both drive type selection (SAS, SSD) and location of these drives in the server modules. Disks that are internal on most server modules are connected by a single port and run at a maximum speed of 3 Gbs.
Disks located in storage modules are connected with two ports and run at a maximum speed of 6 Gbs. Dual port drives provide additional fault tolerance that keep a drive online if the primary port fails. Currently SAS drives support two ports. SATA and SATA SSD drives are single ported.
In consideration of the differences between server modules and drive types, you should take the following into account when configuring your system:
Virtual drives must be composed of drives using the same interface only (for example: SAS only or SATA SSD only).
Virtual drives must be contained in a single failure domain. The internal Sun Blade X3-2B disks are considered to be a single failure domain (single port connections only). One or more Sun Blade 6000 Storage Modules are also considered a single failure domain. Any virtual drive created on the Sun Blade X3-2B is limited to 4 drives, including the hot-spare drives. The number of virtual drives on Sun Blade 6000 Storage Modules can be up to 8 or more drives depending on the number of Sun Blade 6000 Storage Modules accessible to the server module.
Use dedicated hot-spares only. Do not use global hot-spares unless they cannot be accessed by another failure domain.
Dedicated hot-spares should only include drive groups that reside in the same failure domain. Using this method, you can create a "virtual" global hot-spare for any domain.
SATA/SATA-SSD drives are not supported in Sun Blade 6000 Storage Modules. The chassis Zone Manager does not allow you to zone the drives.
Both SAS and SATA drives are supported in Sun Blade X3-2B; however, if used in the server module, the SAS drives do not run at full speed and cannot utilize the second port.
SAS and SATA drives can be mixed in the server module, but not amongst virtual drives. For example you could have a two drive SAS RAID 1 and a two drive SATA-SSD RAID 1 in a Sun Blade X3-2B.