Sun Microsystems 440 To Create a Hardware Disk Mirror, C1t3d0 Devices/pci@1f,700000/scsi@2/sd@3,0

only one device (the master) appears in the device tree. The mirrored device (the slave) is invisible to the operating system, and is accessed only by the Ultra-4 SCSI controller.

Caution – Creating or restoring a disk mirror destroys all data previously stored on the hard drive.

Physical Disk Slot Numbers, Physical Device Names, and Logical Device Names

To perform a disk hot-swap procedure, you must know the physical or logical device name for the drive that you want to install or remove. If your system encounters a disk error, often you can find messages about failing or failed disks in the system console. This information is also logged in the /var/adm/messages files.

These error messages typically refer to a failed hard drive by its physical device name (such as /devices/pci@1f,700000/scsi@2/sd@1,0) or by its logical device name (such as c1t1d0). In addition, some applications might report a disk slot number (0 through 3).

You can use TABLE 3-1to associate internal disk slot numbers with the logical and physical device names for each hard drive.

TABLE 3-1Disk Slot Numbers, Logical Device Names, and Physical Device Names

Disk Slot Number	Logical Device Name*	Physical Device Name
Slot 0	c1t0d0	/devices/pci@1f,700000/scsi@2/sd@0,0
Slot 1	c1t1d0	/devices/pci@1f,700000/scsi@2/sd@1,0
Slot 2	c1t2d0	/devices/pci@1f,700000/scsi@2/sd@2,0
Slot 3	c1t3d0	/devices/pci@1f,700000/scsi@2/sd@3,0

*The logical device names might appear differently on your system, depending on the number and type of add-on disk controllers installed.

▼To Create a Hardware Disk Mirror

1.Verify which hard drive corresponds with which logical device name and physical device name.

See “Physical Disk Slot Numbers, Physical Device Names, and Logical Device Names” on page 57.

Chapter 3 Managing Disk Volumes 57