Sun Microsystems 2500 manual Sun StorageTek 2501 Array, Drive Expansion Tray IOM

Sun StorageTek 2501 Array

The drive expansion tray expands the storage capacity of a storage array. The controllers in the controller tray can connect to the drive expansion tray and access the disk drives in the drive expansion tray for additional storage. A drive expansion tray contains both physical components (disk drives, IOMs, and power-fan assemblies) and logical components (virtual disks and volumes).

Drive Expansion Tray IOM

The drive expansion tray contains two IOMs that provide the interface between the disk drives in the drive expansion tray and the controllers in the controller tray. The IOM also monitors sub-system parameters. Each controller in the controller tray connects to an IOM.

If one IOM fails, the other IOM provides a redundant data path to the disk drives. You can replace a failed IOM while the power to the storage array is turned on and the storage array is processing data (a hot swap).

Drive Expansion Tray IOM Connectors

The IOM connects to the controller tray and drive expansion trays with SAS cables. Each IOM in a drive expansion tray has two SAS expansion connectors. One connector shows an up arrow, and the other connector shows a down arrow.

FIGURE 1-9SAS Connectors on the Drive Expansion Tray IOM

1. SAS Connector (Up

Arrow)

2. SAS Connector

(Down Arrow)

3. Serial Connector

When connecting the SAS cable from an IOM in one drive expansion tray to an IOM in another drive expansion tray, connect from a down arrow to an up arrow. If the cable is plugged into two connectors with arrows of the same direction, communication between the two drive expansion trays is lost.

10 Sun StorageTek 2500 Series Array Hardware Installation Guide • March 2007