Unix switching on and off

It is extremely important that the starting up and closing down procedures are done correctly on multi-user systems, but the procedure is quite simple.

1. Switch on

   Switch the computer on, and wait for prompt:

   Boot :

   Press Return. If you do not press return the system will eventually start up itself.

   You may get the message 'System was not closed down properly - proceed with cleaning? (y/n)' if the system was not closed down properly, e.g. operator error, power cut etc. Answer 'Y'. The system will then proceed with various housekeeping tasks it was unable to complete before the power went off. Ignore the various diagnostic messages unless they are particularly numerous. It is recommended that you then do a validation of the vet. system data.

   Wait for the message: 'Press Control-d or enter root password for system maintenance' and press Control-d.

   The system next displays the date and time like this:

   Current System Time is Thur Nov 4 15:09:00 GMT 1999
   Enter new time ([[CC]YYMMDD]hhmm[.ss]):
   

   If the date and time are correct, press <CR>. If only the time is incorrect, enter the correct time in the format HHMM, e.g. 3.45pm would be entered as 1545 (with no punctuation). If the date is incorrect, enter the date and time in the format YYMMDDHHMM. For example 3.45pm on the 24th January 1999 is entered as 9901451545, again with no punctuation.

   The other terminals will then start up at this point and display the prompt 'Login:'. At this point enter your login name and press <CR> and the vet system will then start up.

2. Start-up diagnostic

   On start-up, after every reboot, on the main console, a vet file system diagnostic will be run through, which will detect major problems such as files missing and corruption at the beginning of files and attempt to repair the damage sufficiently to allow you to get at least as far as loading up the vet system, but will not, of course recover any destroyed data. The program does not deal with missing definition files.

   If you wish to force the program to run through a diagnostic check when one has already been run for that day, delete the file 'testdate' e.g. rm testdate . Please note this program is not a substitute for the validation run, which should still be run at least once a month or in the event of a power failure.

3. Close-down Unix systems: Shutdown

   You do not have to switch the system off at the end of the day and hardware problems are not going to be any more likely if you leave the system on permanently. However, you should certainly make sure all terminals are at the log-in prompt and not left in the vet system.

   If you need to close the system down follow the instructions below:

   On the main console at the 'Log-in' prompt, log-in as 'admin' (with a password of 'admin' and select from the menu the option Shutdown System.

   When closing down, first make sure that all secondary terminals have been closed down and are displaying the 'login:' prompt. This can be checked by using 'Admin' -> 'Utilities' -> 'Who is Logged on', this will show any active terminals.

   If you cannot cannot access the admin account, you should login as root and at the '#' prompt type 'shutdown -g0 -y' and press <CR>.

   Wait until you can see a prompt which says 'Safe to power off' - this is NOT the same as the message 'Unix will now terminate', which occurs about 1 minute earlier. Ignore the lists of processes which are being terminated.

   Then you may switch the system off.

   Important: When you switch the system off, you must wait at least 15 seconds before you switch on again, or you may damage the system.

4. Emergency close-down

   You must NEVER just switch off a multi-user system. It must be closed down correctly. The above instructions tell you to use the main console for closing down, this is not essential. You can if the main console is hung or you are at a remote location and need to close the system down (a power cut is imminent) use a terminal. The procedure is the same, log-in as 'admin' and select 'shutdown'. The only difference will be that the message 'Safe to power off' will not appear. This message will be routed to the main console.

   If you need to close the system down quickly you can use the command 'haltsys'. This will do an immediate close-down. It will not warn other users and should only be used in emergencies.

5. Multiple operating systems

   If you have multiple operating systems (e.g. MSDOS and Unix) installed, you may swap between them. The system will default to Unix (we do not recommend changing this default). To use the MSDOS partition (if installed) at the Boot prompt enter the word 'dos' and press <CR>. The system will then enter the DOS partition. To return to Unix reset the system by pressing <CTRL><ALT><DEL> (remember to let go when the screen clears).