Understanding of SCO Unix Machine startup

The fifth section machine starts the understanding:

1. Start of TCP/IP:

⑴. TCP/IP is controlled by the/etc/tcp script file, starts when you enter the multiuser state, and closes the/etc/tcp file operation when you enter Single-user state: He is a script file that functions as follows: Start or turn off TCP/IP by configuring the streaming devices necessary to support TCP/IP. and start or turn off TCP/IP-related daemon.

⑵. Log in as root and use the command line: TCP Start or TCP stop to manually start or turn off TCP/IP. This file is linked to files in the ETC/RC2.D and/ETC/RC0.D directories, allowing/etc/tcp to run the start or Stop option when the system enters or exits multiuser state. Whether you add or remove a network interface via network Confugration Manager, add or remove ifconfig commands in the script, modify/etc/tcp files, and cause/ETC/STRCF files to be modified. The following is a list of the steps the system is doing when starting TCP/IP:

。 Initializes STREAMS and sockets

。 Sets the host name

。 Configures interfaces

。 Starts Network daemons

。 Undoes all of the above on Shurdown

⑶. /ETC/TCP operation: The TCP/IP core support configuration takes only one time to complete. It mainly includes the Streams module stack for TCP/IP. The system core sets the streams stack at boot time. The prerequisite is that you do not need to ksl.disable the boot string at the boot: prompt. When you set up the streams stack, the/etc/tcp script file invokes the Slink command to establish the streams stack before any other settings or startup.

2. UNIX5 Startup:

㈠. UNIX5 can be divided into six basic steps:

1. The PC BIOS will mount the master Boot block into memory. (Read the track 0, sector 0 information on the hard drive

2. The Master boot block loads the partition boot blocks (boot0). (Read the information at the sector0 of the active partition).

3, if the Unix partition is active, then continue to load into the boot1.

4, Boot1 loaded into the/stand/boot. (Read the UNIX bootable file system area for information, typically the boot file system)

5./stand/boot is responsible for executing all the commands found in the. Bootrc and reading the parameters in the/stand/etc/default/boot file.

6,/stand/boot Display boot: prompt, successful boot.

7,

㈡. Description of UNIX5 Startup:

1,/stand is the UNIX5 default boot system/dev/boot hang contact. The general mark is read only. If you want to modify the contents, you must uninstall it and then mount it again.

2. Bootrc is especially useful in network installations, where a packet driver and TFTP driver could have to be load before User can load a kernel from network.

3, in the boot: you can use the external Bootos program. Bootos can identify the identification of: CCPM (Concurrent cp/m), DOS, DOS_12/16/32, Dos_ext, NT, OS2, Os2.hpfs, UNIX, Xenix and so on.

Available Bootos? Lists the existing installed file systems. The Bootos is followed by a partition ID or an area code to boot the corresponding system.

4, unix5 generally have four cores, stored in the/stand directory. In addition to UNIX and Unix.old, the other two cores are Unix.install (original core backup on the installation disk), Unix.safe (backup after the first heavy core).

3. UINX5 's command:

4. Some of the most commonly used commands are:

First, PS

We can use the PS –l option to get more detailed information about the process.

f (Flag): A series of numbers that represent the current state of a process. The meaning of these numbers is:

00: If shown separately, this process has been terminated.

01: The process is part of the core process and resides in system main memory. Such as:

Sched, Vhand, Bdflush and so on.

02:parent is tracing process.

04:tracing Parent ' s signal has stopped the process; The parent is Waiting (Ptrace (S)).

10: The process goes into hibernation when the priority is less than or equal to 25 o'clock, and cannot be awakened with a signal, for example, while waiting for an inode to be created

20: The process is loaded into main memory (primary memory)

40: The process is locked in main memory and cannot be replaced until the transaction is completed

s (State of the process)

O: The process is running on the processor

S: Sleep state (sleeping)

R: Waiting to run (runable)

I: Idle state (idle)

Z: Zombie State (Zombie)

T: Trace status (traced)

B: The process is waiting for more memory pages

c (CPU Usage): Estimated value of CPU utilization