Kaypro 10 - Page 130

When all files have been processed (restored or skipped), the program will
terminate and you will see the message:
END
OF RESTORE. ALL FILES CLOSED
In the example above, we wanted to restore only one of the four or iginal files .
This may not be a good idea if the files are logically interrelated . Depending
upon
the type of processing you are doing and the amount of work done since
the backup, you may foul up your system by restoring only some files.
The " Remove it?" question will only be asked if the file already exists on the
hard disk which you specified. If you plan to restore all of the files from a par-
ticular backup , you may wish to erase them from the hard disk before running
MUFREST. For example: you could type .. .
A> ERA
FILE?DAT
A>MUFREST
You would then be relieved of answering YES to all of the "Remove it?"
questions.
5.0 INFORMATION ABOUT RANDOM ACCESS FILES
One
aspect of this system which we have not discussed concerns random ac-
cess files . In CP/M, when you write in random access mode, only those extents
and records to which you have actually written will have disk space allocated to
them. For example, if you open an empty file and write to record number 1, 000
in random access mode, there will not be space allocated for records 1 through
999. When the backup program reads the source file, it sequentially reads in
random mode . In the case of the file described above, the program will detect
the fact that no data exists for the first 999 records. When MUFBACK finds such
records , it will write a block of 128 NULLS (ASCII code zero) to the destination
file. Upon restoration , there will be ALL 1000 records on disk. Those records
not previously allocated will now contain NULLS.
This may affect your processing in two ways.
First,
any files which have numerous "holes" in them will likely require more
disk space after restoration than the original files did.
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