Page 5-10
Chapter Five
AM-6060 Computer Owner's Manual, Rev. 00
ANALYZING THE DISK
A disk diagnostic program reads data from a disk. If it cannot read an area of the disk, it reports the
problem to you. Checking your disk frequently with disk diagnostic programs helps prevent data loss—
the sooner you catch a malfunction, the less data is likely to be affected.
The type of problem found by disk diagnostics is known as a "hard error," because it means data is lost.
A "soft error" means the computer had trouble reading the data, but data was not lost. Disk diagnostics
do not report soft errors.
If a diagnostic program indicates problems, you may need to restore data from a backup copy or
reconstruct the data on a damaged disk. If you have this type of problem, consult the section "Recovering
From Disk Errors" in the System Operator's Guide.
Before running any of the disk diagnostic tests, especially if you suspect a problem, it is a good idea to
use the SET DSKERR command:
SET DSKERR
RETURN
SET DSKERR causes the computer to report the location of any hard errors the diagnostic program
finds. If you don't use SET DSKERR, the diagnostic tells you only that an error occurred, not where on
the disk it happened. You must run the diagnostic program from the same job where you used SET
DSKERR.
The next two sections discuss two very useful diagnostic programs, REDALL and DSKANA. You can
find more information on disk diagnostic programs in the System Operator's Guide and the AMOS User's
Guide.
The REDALL Command
REDALL reads every block of data—or the number of blocks you choose—on the disk you specify, and
reports any hard errors. It does not alter the data on your disk.
It is a good idea to run REDALL for each disk on your computer occasionally, possibly once a week.
That way, if any disk problems develop, you can be sure to detect them quickly.
To use REDALL, perform these steps:
1. To read all the blocks on a disk, enter REDALL followed by the device name of the disk you
want to read. For example:
REDALL DSK2:
RETURN
2. If you don't want REDALL to read all blocks on the disk, follow the disk specification with the
number of blocks you want read:
REDALL DSK2:100
RETURN
The command above tells REDALL to read the first 100 blocks on DSK2:.
