This chapter describes the function and physical components of the SGI TP900 storage module in the following sections:
The SGI TP900 storage unit is a 2U-high 8-drive storage system that provides compact, high-capacity, high-availability JBOD (just a bunch of disks) storage. The enclosure backplane connects the 8 drives on one SCSI bus. As an option, the storage unit can also be configured on two SCSI buses (two strings of four drives).
This storage unit has the following features:
Mounts in a standard 19-in. rack; available in factory-installed configurations with the Origin 3900 servers.
Uses SCSI Parallel Interface 3 (SPI-3) capable Low Profile (1-inch high) 3.5-inch disk drives.
Its drive carriers accept SGI-qualified 10,000- or 15,000-RPM U160 SCSI disk drives.
Supports 36 GB and 146 GB drive capacities.
Note: For more information about the TP900 storage module, see the SGI Total Performance 900 Storage System User's Guide.
This section describes the external components located on the front and rear panels of the TP900 storage module.
The front of the SGI TP900 storage module consists of 8 drive bays that contain either disk drive carrier modules or dummy carrier modules. The storage module is 4 bays wide by 2 bays high. The bays are numbered 1 and 2 from top to bottom, and 1 to 4 from left to right. See Figure 10-1.
The disk drive carrier module is a die-cast aluminum carrier that houses a single 1.0-in. high, 3.5-in. wide disk drive. This carrier has a handle that enables you to insert and remove the carrier from the drive bay. The handle also has an anti-tamper lock that locks the handle in place; therefore, the carrier cannot be accidentally removed from the drive bay. When the handle is locked, a red indicator is visible in the handle. When carrier is unlocked, a white indicator is visible.
Each drive carrier has two LEDs: an upper green LED and a lower amber LED. In normal operation, the green illuminates and flickers as the drive operates. The amber LED illuminates when a fault occurs. See Figure 10-2 for the locations of LEDs.
Dummy carrier modules are provided for installation in all unused drive bays. They are designed as integral drive module front caps with handles. They must be installed in unused drive bays to maintain a balanced airflow.
The front of the chassis also contains three status LEDs that are described in Table 10-1.
LED | Status |
|---|---|
System status | Green signifies that power is applied to the enclosure. |
Power status | Green signifies that the power supplies are functioning normally. |
Cooling status | Green signifies that all fans are functioning normally. |
The rear of the TP900 storage module contains 6 bays that house power supply, cooling, and SCSI I/O modules. See Figure 10-3. The rear of the TP900 storage module is 3 bays wide by 2 bays high. The bays are numbered 1 and 2 from top to bottom, and 1 to 3 from right to left.
The TP900 rear bays house the following components:
Power supply module. The SGI TP900 storage system requires one 350-W power supply module, which is mounted in the rear of the system (location 2/3). Power supply voltage operating ranges are nominally 115 V or 230 V and are selected automatically.
Optionally, a second power supply module (location 2/1) can be added to the TP900 system to provide n+1 redundant power. In this n+1 redundant configuration, the power supply modules operate together; if one power supply module fails, the other module supplies power until the faulty unit is replaced.
The power supply module contains two LEDs that are located on the front panel of the power supply. The green LED indicates power output. The amber LED indicates a power supply failure.
Note: When you order a TP900 storage module with redundant power, it will also have redundant cooling (two cooling modules). Input/output (I/O) module. The I/O module contains two VHDCI connectors and a switch to set the SCSI ID range. The SGI TP900 storage module supports 1 I/O module for a 1 x 8 configuration and 2 I/O modules for a 2 x 4 configuration. The 1 x 8 configuration creates a SCSI bus structure with 1 string of 8 drives. The 2 x 4 configuration creates a SCSI bus structure with 2 strings of 4 drives.
Note: When only one I/O module is present in the system, the other I/O module location contains a loopback module that has no external connectors. Loopback module. The backplane of the TP900 consists of two 4-drive channels. A loopback module is used to connect the two internal drive channels together when the TP900 is configured as one channel with 8 drives.
Cooling module. The cooling module consists of fans that pull warm air from a plenum behind the drive backplane and exhaust the warm air at the rear of the enclosure. The cooling modules connect to the backplane for power and status signal connections.
The TP900 system requires one cooling module, which is mounted in the rear of the system. Optionally, a second cooling module can be added to the system to provide redundant cooling. In this redundant configuration, the cooling modules operate together; if one module fails, the other module adequately cools the system until the faulty unit is replaced.
Note: When you order a TP900 storage module with redundant cooling, it will also have redundant power (two power supply modules). Blank module. Blank modules are placed in all vacant power supply and cooling module bays to maintain proper airflow through the system.
Terminator plug. Each I/O module has two 68-pin VHDCI connectors. A host bus adapter is connected to one of the VHDCI connectors and a terminator plug is placed in the remaining connector. Figure 10-4 shows the terminator plug.
Table 10-2 lists the specifications of the TP900 storage module.
Table 10-2. TP900 Storage Module Technical Specifications
Characteristic | Specification |
|---|---|
Height | 3.37 in. (85.7 mm) |
Width | 17.6 in. (447 mm) |
Depth | 21.46 in. (545 mm) |
Weight: |
|
Input power | 100-254 VAC (~175 W) |
Table 10-3 lists the available configurable items for the TP900 storage module.
Table 10-3. Configurable Items
Configurable Item | Options |
|---|---|
Disk drive | 18 GB (1 minimum, 8 maximum) |
I/O module | 1 minimum, 2 maximum |
Cooling module | 1 minimum, 2 maximum |
Power supply module | 1 minimum, 2 maximum |