Installation and User's Guide

Preparing the storage unit

This section explains how to remove the CRUs and set the option switches to prepare the storage unit for installation.

Removing CRUs

Attention: Static electricity, though harmless to you, can seriously damage storage unit components or options. See Handling electrostatic discharge-sensitive devices for details.

Attention: If you have data stored on the drives, label the drives before you remove them. Then, when you replace the drives, install each one in the same drive bay from which you removed it. Failure to do so could result in a loss of data.

See "Installing and replacing devices", for information on removing the CRUs.

It is easier to lift the storage unit and install it in a rack if you remove all CRUs (disk drives, power supplies, and ESMs) first. A fully loaded storage unit with 14 hard disk drives and two power supplies installed weighs 36.1 kg (79.5 lb). The standard unit with two power supplies weighs 22.5 kg (49.5 lb). If you remove all the CRUs, you can reduce the overall weight.

Statement 4
>=18 kg (37 lb)	>=32 kg (70.5 lb)	>=55 kg (121.2 lb)
Caution: Use safe practices when lifting.

Setting the interface options and ID settings

When you install a drive CRU in the storage unit, the drive tray plugs into a printed circuit board called the midplane. The midplane sets the SCSI bus number and ID automatically.

The switch card located on the back of the storage unit has five external option switches, four internal option switches, and a unit ID switch. It is easier to set these switches before you install the storage unit in a rack or tower enclosure.

Attention: Always set the option switches while the storage unit and host server are turned off. Failure to do so will result in loss of data. See "Switching the storage unit on and off".

External option switches

The five option switches on the exterior of the switch card are: Option switch 1 controls the power supply to the storage unit. Option switches 2 through 5 are reserved; leave these switches in the default positions.

Option switch 1 -- Power-control switch

When this option switch is set to Off, the storage unit turns on and off automatically when you turn the host machine on and off. This occurs only if termination power is present (the termination-power LED is on) at the external SCSI connector.

When this option switch is set to On (the default), you must turn the storage unit on and off separately.

Option switches 2 through 5 -- Reserved

These option switches are reserved; leave these option switches set to the default positions. Set switches 2 through 5 (On, On, Off, Off) respectively.

Internal option switches

All internal option switches must be set in the Off (default) position.

Unit ID switch

The unit ID switch has 10 settings. You can use these settings (0 through 9) to set an ID for the storage unit. System-management software uses this storage unit ID when it provides data and alerts for the storage unit.