Determining the Interface of a Peripheral Device

Refer to the documentation that accompanies your hardware to determine the interface of the device. Peripheral devices typically use one of the following interfaces:

• Small Computer System Interface (SCSI)
• Intelligent Peripheral Interface (IPI)

In many cases, an external device is cabled to a connector that is part of a SCSI card. However, in some cases an external peripheral device is cabled to an onboard (built-in) SCSI connector. An onboard SCSI connector is usually part of the main logic board.

Determining Peripheral Buses of a Sun System

You must determine the type of peripheral bus that your Sun^(TM) system supports. As shown in Table 6-1, there are two types of peripheral buses:

Table 6-1

Peripheral Bus	SCSI	IPI
SBus	Built-in and cards	Not supported
VMEbus	Boards	Boards

Your Sun system may have one or both types of peripheral buses. For information on the type of peripheral bus that your system has, refer to the documentation that accompanies your hardware.

Typically, your sales representative provides you with the right interface card to fit the peripheral bus of your system and the type of interface that the peripheral device supports. Many systems have built-in SCSI support, and you would not need to install any additional cards.

Determining the Interface of a Sun System

You must determine the type of interface that your peripheral device requires before you can continue. If you have a peripheral device, such as a disk drive, that requires a SCSI interface, then your Sun system must also have a SCSI interface.

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Note - Your Sun system may not support these interfaces unless you install additional SCSI or Interface Controller boards. The documentation that accompanies your hardware provides information on the types of interfaces that your system can support.

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If the particular interface that your peripheral device needs requires you to install a card in your Sun system, make sure that you use a SCSI, IPI, serial, or parallel interface card that is designed for the peripheral bus of your Sun system.

Determining Address Selection Schemes

To configure disk drives, tape drives, CD-ROM drives, printers, and modems, you need to understand the address selection scheme that your system uses for the specific peripheral device that you want to configure. Address selection schemes for disk drives differ from address selection schemes for tape drives. This section discusses the address selection schemes for different types of peripheral devices.

Determining the Address Selection Scheme for Disk Drives

Make sure that your Sun system supports the interface that your drive requires. As most external drives require a SCSI interface, you may be able to connect them to the built-in SCSI connector of your Sun system. If your Sun system does not have built-in SCSI support, you have to install an additional SCSI card in your SBus or VMEbus. If you plan to connect a drive that requires IPI support, you must install an Interface Controller board in the VMEbus.

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Note - The Solaris 2.5.1 operating environment supports up to seven disk drives or CD-ROM drives on one SCSI bus, provided the cable does not exceed 6 meters. However, the Solaris 2.5.1 operating environment supports up to fifteen drives or CD-ROM drives on one wide SCSI bus provided the cable does not exceed 25 meters and has a differential interface.

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Your Sun system uses logical controller ID Numbers, logical bus target ID numbers, logical disk ID numbers, and logical slice (often referred to as "partition") numbers to access specific areas on a given disk drive. A combination of all these ID numbers make up a device address for the drive. (This is sometimes called a logical name.)

A typical device address for a disk drive assigned by the Solaris 2.5.1 operating system would be:

c0t1d0s0

A typical device address for a CD-ROM drive assigned by the Solaris 2.5.1 system would be:

c0t6d0s0

The address selection scheme for disk drives that the Solaris 2.5.1 system uses is shown in Figure 6-1.

The Solaris 2.5.1 operating environment automatically assigns a device address to each internal and external disk drive connected to your Sun system based on the target ID number of the device and the controller board to which it is connected.

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Caution - Before the Solaris 2.5.1 system can assign a device address to an external disk drive, the disk drive must have been connected to your Sun system and powered on. If you have connected the external disk drive to your Sun system but have not powered it on, the Solaris 2.5.1 operating system cannot detect the presence of this disk drive. Therefore, the operating system is unable to assign a device address to that external disk drive. Internal disk drives are automatically detected.

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Logical Controller ID Number

Logical controller ID numbers, such as c0, c1, c2, etc., are automatically assigned in sequential order to each interface card to which disk drives are connected. The interface cards can be located in either an SBus or a VMEbus.

The operating system probes and polls the interface cards one by one. If your Sun system has built-in SCSI support, the operating system automatically assigns 0 to that "card." Therefore, any disk drives that are connected to the built-in SCSI "card" have a device address that starts with c0.

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Note - If you move an SBus card to another slot or replace a card with a different type of card at the same location, the logical controller ID number might not be as you expected. A number that was in use earlier might be skipped when ID numbers are assigned to controllers in their new locations. (This situation is sometimes called persistent instance numbering.)

Because of the persistence of old logical controller ID numbers, you must update the /etc/vfstab file after changing the location or type of cards in SBus slots. For more about editing the /etc/vfstab file, see man Pages(4): File Formats and the System Administration Guide, Volume I manual.

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Logical Target ID Number

Logical target ID numbers, such as t0, t1, t3, correspond to the address switch setting that you select for each disk drive. All external disk drives have an address switch that is located on the rear panel. The default switch setting for Sun CD-ROM drives is 6. Internal SCSI disk drives usually have jumper settings that have been preset by the factory to 3, as shown in Table 6-2 on page 73. If your system has a second internal SCSI disk drive, it is usually set to 1 by the factory.

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Note - Jumper settings serve the same purpose as address switch settings. They provide a unique address for a disk drive.

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If you want to find out the current switch or jumper settings, you can use the probe-scsi or the probe-ipi commands at the ok prompt. The probe-scsi command returns the drive's logical target number and device type (name). The probe-ipi command returns similar information about disk drives that have an IPI interface.

The probe-scsi-all command provides information on devices that are connected to any SBus located on a server other than the on-board SBus, provided this command is supported by the boot PROM on your system.

You must set the address switch on all external disk drives. As you can have up to seven devices daisy-chained to each SCSI or Interface Controller board, you must assign and set a unique address (number) for each disk drive.

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Caution - The logical controller ID numbers are automatically assigned by the Solaris 2.5.1 operating system. However, you set the logical target ID numbers. They are detected or polled on each disk drive by the operating system.

You must have unique addresses selected for each device in each daisy chain. If you accidentally select the same address on two different disk drives that are connected to the same interface card, the Solaris 2.5.1 system will not be able to poll correctly. Therefore, you will not have access to that drive and may not be able to load the system. If this happens, reset the address switch on one of the disk drives.

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Table 6-2 on page 73 provides an example of how the Solaris 2.5.1 system assigns device names to internal and external disk drives in a Sun system that has both an SBus and a VMEbus. In the example shown in Table 6-2 on page 73, the Sun system has built-in SCSI support for three attached hard disk drives and one CD-ROM player; it also has two additional SCSI interface cards that are located in the SBus. Each of the SCSI cards has three external disk drives attached. In addition, this system has two IPI cards that are located in the VMEbus. Each of the IPI cards has three external disk drives attached.

Table 6-2

Disk Drives	Built-In SCSI Support	First SCSI Interface Card	Second SCSI Interface Card	First IPI Interface Card	Second IPI Interface Card
First internal disk drive	c0t3
Second internal disk drive; if you do not have a second internal disk drive, you can use this address for your first external disk drive.	c0t1
First external disk drive that is connected to the built-in SCSI connector	c0t2
Second external disk drive	c0t0
CD-ROM player	c0t6
First external disk drive		c1t1
Second external disk drive		c1t2
Third external disk drive		c1t3
First external disk drive			c2t1
Second external disk drive			c2t2
Third external disk drive			c2t3
First external disk drive				c3t1
Second external disk drive				c3t2
Third external disk drive				c3t3

Table 6-2 (Continued)

Disk Drives	Built-In SCSI Support	First SCSI Interface Card	Second SCSI Interface Card	First IPI Interface Card	Second IPI Interface Card
First external disk drive					c4t1
Second external disk drive					c4t2
Third external disk drive					c4t3

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Note - If you have an SBus-based Sun system, only the SCSI information applies.

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Logical Disk ID Number

Logical disk ID numbers, such as d0, are assigned by the Solaris 2.5.1 system as follows:

• The logical disk ID number is set to 0 for any disk drive that is attached to a target controller that doesn't support multiple logical units.
• A target controller that supports multiple logical units assigns the logical disk ID numbers as d0, d1, etc.

Logical Slice (Partition) Number

Logical slice, or partition, numbers range from 0 to 7. To specify an entire disk, use slice 2. If you have a disk drive that has a logical bus target number of 1 and is supported by the built-in SCSI interface, the Solaris 2.5.1 operating system assigns logical slice or partition numbers as follows:

c0t1d0s0 c0t1d0s1 c0t1d0s2 c0t1d0s3 c0t1d0s4 c0t1d0s5 c0t1d0s6 c0t1d0s7

Displaying Addresses of Connected Disk Drives

Use the format utility to display addresses of connected disk drives. This section provides two examples:

• Addresses in an SBus system
• Addresses in a system that has both types of peripheral buses:

  · SBus

  · VMEbus

· Displaying Addresses of Disk Drives in an SBus

To display addresses of connected and powered-on disk drives in an SBus system:

* Type:

# format Searching for disks...done

If you only want to display the disks that are connected to a specific controller, for example, c2, type:

# format /dev/rdsk/c2* Searching for disks...done

The following display is based on an SBus-based system with built-in SCSI support. No additional SCSI cards have been installed. The system has one internal and one external hard disk drive.

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Note - Device addresses for CD-ROM drives are not displayed by the format utility because the CD-ROM disk drive is a read-only device.

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The Solaris 2.5.1 system has assigned c0 as the logical controller ID number to all SCSI disks because they are supported by the built-in SCSI interface. The jumpers on the first internal hard disk have been set to 3 by the factory, resulting in a logical bus target ID number of 3 (t3).

The address switch on the first external hard disk has been set to 0, resulting in a logical bus target ID number of 0 (t0). The address switch on the CD-ROM drive has been set to 6 by the factory and was not changed resulting in a logical bus target ID number of 6 (t6).

The following information is displayed:

AVAILABLE DISK SELECTIONS: 0. c0t3d0 <SUN0207 cyl 1214 alt 2 hd 9 sec 36> /sbus@1,f8000000/esp@0,8000000/sd@3,0 1. c0t0d0 <SUN0207 cyl 1214 alt 2 hd 9 sec 36> /sbus@1,f8000000/esp@0,8000000/sd@0,0 Specify disk (enter its number):

Table 6-3 shows the device name and path for each disk drive and the CD-ROM drive in this example.

Table 6-3

Type of Device	Device Name	Device Path
First internal disk (built-in SCSI support)	c0t3d0s0...7	/devices/sbus@1,f8000000/ esp@0,8000000/sd@3,0:..
First external disk (built-in SCSI support)	c0t0d0s0...7	/devices/sbus@1,f8000000/ esp@0,8000000/sd@0,0:..
CD-ROM player (built-in SCSI support)	c0t6d0s0...7	./devices/sbus@1,f8000000/ esp@0,8000000/sd@6,0:..

· Displaying Addresses in an SBus and in a VME Bus

To display the current setup of connected and powered-on disk drives in a Sun system with an SBus and a VMEbus:

* Type:

# format Searching for disks...done

The following display provides an example of a system with an SBus and a VMEbus:

AVAILABLE DISK SELECTIONS: 0. c0t1d0 <SUN0669 cyl 1614 alt 2 hd 15 sec 54> /iommu@f,e0000000/sbus@f,e0001000/dma@f,81000/esp@f,800000/sd@1,0 1. c0t2d0 <SUN0669 cyl 1614 alt 2 hd 15 sec 54> /iommu@f,e0000000/sbus@f,e0001000/dma@f,81000/esp@f,800000/sd@2,0 2. c1t0d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@0,0/id@0,0 3. c1t1d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@0,0/id@1,0 4. c2t0d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@1,0/id@0,0 5. c2t1d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@1,0/id@1,0 6. c2t2d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@1,0/id@2,0 7. c2t3d0 <Seagate IPI ZBR Elite cyl 1893 alt 1 hd 17 sec 78> /iommu@f,e0000000/vme@f,df010000/SUNW,pn@4,d,1080000/ipi3sc@1,0/id@3,0 Specify disk (enter its number):

This example shows a server with built-in SCSI support (c0) to which two internal hard disk drives (sd@1,0 and sd@2,0) are connected. This system has two additional IPI cards (c1 and c2). The SCSI jumper switches on the disk drives have been set to 1 and 2 (t1 and t2).

There are two external disk drives (id@0,0 and id@1,0) connected to the first IPI card (c1). The IPI address switches on the disk drives have been set to 0 and 1 (t0 and t1).

There are four external disk drives (id@0,0, id1@1,0, id@2,0, and id@3,0) connected to the second IPI card (c2). The IPI address switches on the disk drives have been set to 0, 1, 2, and 3 (t0, t1, t2, and t3).

Table 6-4 shows the device name and path for each disk drive.

Table 6-4

Type of Device	Device Name	Device Path
First internal disk (built-in SCSI support)	c0t1d0s0...7	/iommu@f,e0000000/sbus@f,e0001000/dma@f,81000/esp@f, 800000/sd@1,0:a...h
Second external disk (built-in SCSI support)	c0t2d0s0...7	/iommu@f,e0000000/sbus@f,e0001000/dma@f,81000/esp@f, 800000/sd@2,0:a...h
First external disk attached to first IPI card in VMEbus	c1t0d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@0,0/id@0,0:a...h
Second external disk attached to first IPI card in VMEbus	c1t1d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@0,0/id@1,0:a...h
First external disk attached to second IPI card in VMEbus	c2t0d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@1,0/id@0,0:a...h
Second external disk attached to second IPI card in VMEbus	c2t1d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@1,0/id@1,0:a...h
Third external disk attached to second IPI card in VMEbus	c2t2d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@1,0/id@2,0:a...h
Fourth external disk attached to second IPI card in VMEbus	c2t3d0s0...7	/iommu@f,e0000000/vme@f,df010000/SUNW,pn@4d,1080000/ ipi3sc@1,0/id@3,0:a...h