This chapter describes the actions to take when you are faced with various system problems. You may have to correct a problem with the file system, act immediately after a power failure, or remove the CI from system use. There may be times when you cannot trace a problem.
At such times, Digital Field Service can remotely run diagnostic programs on your system. The following sections address these topics.
Errors that require you to correct a problem in the file system seldom occur. However, if a problem of this nature arises, you can perform four classes of file system corrections. From the least to most severe, they are:
o Restore a single file in a directory
o Restore a single directory (other than <ROOT-DIRECTORY»
o Restore <ROOT-DIRECTORY>
o Restore the entire file system
The TQe§=~Q QQ~r~~Qr~~ g~!g~ provides all the necessary for the operator to correct these types of problems.
through 9.4 provide you with an overview of how these solved.
9.1 RESTORING A SINGLE FILE
information Sections 9.1 problems are
If you receive a request to restore a file for a user, you can use the following procedure.
1. Look in the binder that contains the listing of the DUMPER log files. (Chapter 7 describes creating DUMPER log files.)
9-1
SYSTEM PROBLEMS/CRASHES
2. Write down the file specification (including the structure and directory) to be restored, and the date and number of the tape containing the file. Be sure to indicate the destination structure and directory if one or both are different from the structure and directory from which the file was saved.
3. Submit a request to the operator to restore the file.
9.2 RESTORING A SINGLE DIRECTORY
If you receive a request to restore a directory, you can use the following procedure.
1. Determine the structure that contains the directory.
2. Make sure you have a copy of the files in this directory on a DUMPER tape. (Check the log files.)
3. Give the AECREATE command with the LIST subcommand. Write down the list of parameters, for example, the directory number, allocation, etc. You may need this information when you re-create the directory.
4. Give the AECREATE command with the KILL subcommand for the directory. (The IQ~§:~Q QE~r~~2r:~ Q~!Q~ provides additional procedures for deleting a single directory if the AECREATE command with the KILL subcommand is unsuccessful.)
5. Using your DUMPER backup tapes, first restore the files from the last FULL-INCREMENTAL DUMPER operation. Then, restore files from each INCREMENTAL tape until the time when the files were lost. Be sure the operator gives the CREATE command to DUMPER to restore the directory parameters.
If the directory contains unreproducible information and it is not backed up on tape, call Digital Software Services for assistance. It
!~~ be possible to reconstruct the directory without losing the valid information in it.
9.3 RESTORING <ROOT-DIRECTORY>
Each structure has its own <ROOT-DIRECTORY> and a backup
<ROOT-DIRECTORY> that is used by the system if the primary
<ROOT-DIRECTORY> is bad. The directory <ROOT-DIRECTORY> contains a pointer to each first-level directory on a structure, as well as several important system files. (Chapter 5 illustrates how
<ROOT-DIRECTORY> points to directories.) If <ROOT-DIRECTORY> is lost
SYSTEM PROBLEMS/CRASHES
on the public structure, users cannot access any files in the system.
If <ROOT-DIRECTORY> is lost on a mountable structure, users cannot access files on that structure.
You can tell that the <ROOT~DIRECTORY> on the public structure is bad if the operator's console prints anyone of the BUGHLTs listed in Table 9-1. When a BUGHLT appears on the console, the system stops. A BUGHLT appears in the form:
**********
*BUGHLT name AT dd-mm-yy hh:mm:ss
*JOB:n, USER: user-name
*ADDITIONAL DATA: data, data, data
**********
The lines beginning with JOB: or ADDITIONAL DATA: may not appear.
Table 9-1: <ROOT-DIRECTORY> BUGHLTS
BUGHLT Meaning
BADROT <ROOT-DIRECTORY> is invalid
FILIRD The system could not initialize <ROOT-DIRECTORY>
FILMAP The system could not map <ROOT-DIRECTORY> into memory
BADXT1 The index table is missing and cannot be created '<ROOT-DIRECTORY> may also be bad if you get the BOOT error ?FIL NOT FND. If this error appears, be sure you have mounted all devices correctly.
To recover from a bad <ROOT-DIRECTORY>, first determine which structure contains the bad directory. If the bad <ROOT-DIRECTORY> is on a mountable structure, you can run CHECKD with RECONSTRUCT ROOT-DIRECTORY and specify the proper structure. The TOPS-20 QE~r~~2r~~ g~!g~ details the procedure for determining the st;~~t~;~
and using CHECKD for reconstructing <ROOT-DIRECTORY> on mountable structures.
If the bad <ROOT-DIRECTORY> is on the public structure, instruct the system to use the backup public
<ROOT-DIRECTORY> and rebuild this directory. Section 9.3.1 this procedure.
9-3
you can structure describes
SYSTEM PROBLEMS/CRASHES NOTE
If your first attempt to rebuild <ROOT-DIRECTORY>
fails, call your DIGITAL Field Service Representative.
~R try to rebuild this directory twice on any structure.
9.3.1 Rebuilding the Public Structure <ROOT-DIRECTORY>
To rebuild <ROOT-DIRECTORY> on the public structure, halt the central processor and perform Steps 7 through 18 and Steps 36 and 37 in Chapter 2 of the !Qe§=~Q ~~!Q MQQ~l ~ !Q~~~ll~~!QQ g~!Q~~ The steps are shown below for reference.
1. Type CTRL/backslash on the operator's console; the system prints PAR>.
2. Type SHUTDOWN and press the RETURN key; the system prints a few message lines.
PAR> SHUTDOWN <RET>
* *
HAL TED* *
%DECSYSTEM-20 NOT RUNNING
3. Mount System Floppy A in drive 0 (Step 7).
4. Mount System Floppy B in drive 1 (Step 8).
5. Mount the TOPS-20 Installation Tape on MTAO: (Step 9).
If the TOPS-20 Installation Tape is not your most recent system backup tape, mount your SYSTEM BACKUP TAPE that contains the monitor, TOPS-20 Command Processor, DLUSER, DLUSER data, DUMPER, and save sets containing <SYSTEM> and
<SUBSYS>. (Refer to Section 3.2 for a description of special system directories.)
6. Place the front-end HALT switch in the ENABLE position (Step 10).
7. Set the front-end switch register to 000007 (octal) (Step 11).
8. Press the ENABLE and SWITCH REGISTER switches simultaneously (Step 12).
RSX-20F YB14-45 8:55 1-JAN-81 [SYO: REDIRECTED TO DXO:]
SYSTEM PROBLEMS/CRASHES [DXO : MOUNTED]
[DX1 : MOUNTED]
KLI -- VERSION VB12-26 RUNNING
KLI -- ENTER DIALOG [NO,YES,EXIT,BOOT]?
KLI> following question appears previous to the question in Step 11. (Step 15.)
KLI -- RECONFIGURE CACHE (FILE,ALL,YES,NO)?
Type ALL and press the RETURN key (Step 16).