The Boot Command
The easiest way to boot a system from the powered-down state is, of course, to turn it on. When you turn a system on, the system locates the boot device using information stored in its NVRAM and starts loading various boot software, as described earlier. If you interrupt this process with a Stop-A or your auto-boot? NVRAM parameter (discussed later in this chapter) is set to false, you can choose to boot from a different device or explore the OpenBoot environment.
The full syntax of the boot command is as follows:
boot device-specifier filename options
Here device-specifier is one of a number of devices that can supply the boot software, filename is the name of the program to be booted (e.g., stand/diag), and options can be either -a, so that you are prompted for the name of boot file; -h, which will halt the boot process after the program specified as filename has been loaded; or -r, which rebuilds device drivers on boot-up (needed if you add a disk or other SCSI device to the system). You can also specify the run state that you want to assume, if you want to assume a run state other than the default one.
To boot from a device other than the default one (boot disk), there must be a bootblock available on the device in question. If, for example, you want to boot from diskl, which corresponds to /sbus/esp/sd@1,0 (the default disk is /sbus/esp/sd@3,0), you must have at some point used the installboot command to create a bootblock on this disk (see the "Setting up an Alternate Boot Disk" section later in this chapter). To boot off the network, you must have prepared a boot server to accommodate this system as a boot client.
HNOUE The drive designators that are used at this point resemble the Solaris 1 naming conventions more than those used in Solaris 2. Regardless, they refer to the same devices as those you'll see on a booted system as /dev/dsk/ c0tid0s0, and so on.
You can alternately boot from other devices (if they are set up for this), including (but not limited to) those listed in Table 3.2.
These labels (e.g., cdrom) are not the actual addresses of the devices, but are device aliases that make it easier to refer to any of these devices. The defined device aliases will differ from one system to the next. You can obtain a complete listing of the device aliases on a system with the OpenBoot firmware's devalias command. A list of typical aliases is displayed in Table 3.3. The device aliases provide the location of the device drivers.
To establish a new alias, use the nvalias command (nvalias alias device-path). For example, if you want to refer to your alternate boot disk as altdisk, you can create that alias with the following command, provided you have a bootblock installed on this disk:
nvalias altdisk /sbus/esp/sd@2,0
|
Table 3.2 Alternate Boot Devices | |
|
DEVICE ALIAS |
CONDITION |
|
cdrom |
You must have the installation CD in your |
|
drive. | |
|
disk2 (the second disk) |
The disk must contain a bootblock. |
|
floppy |
You must have a boot floppy disk in your drive. |
|
net (Ethernet) |
You must have a boot server prepared to support the local system. |
tape You must have a boot tape in your drive.
tape You must have a boot tape in your drive.
The nvunalias command deletes an alias.
HIJ A useful convention might be to create an altdisk alias on all systems that have an alternate boot disk available. Then, regardless of which of the attached disks is serving as the alternate boot disk on a particular system, you can use the same command for booting from it.
|
Table 3.3 |
Typical Device Aliases | |
|
ALIAS |
BOOT PATH |
DESCRIPTION |
|
disk |
/sbus/esp/sd@3,0 |
Default disk |
|
disk1 |
/sbus/esp/sd@1,0 |
Second internal disk |
|
disk2 |
/sbus/esp/sd@2,0 |
First external disk |
|
disk3 |
/sbus/esp/sd@0,0 |
Second external disk |
|
floppy |
/fd |
3.5" diskette |
|
tape |
/sbus/esp/st@4,0 |
First tape drive |
|
tape0 |
/sbus/esp/st@5,0 |
Second tape drive |
|
cdrom |
/sbus/esp/sd@6,0:c |
CD-ROM, partition c |
|
cdroma |
/sbus/esp/sd@6,0:a |
CD-ROM, partition a |
|
net |
/sbus/le |
Ethernet |
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