FixBadPageDoc.tioga
Copyright © 1986 by Xerox Corporation. All rights reserved.
Willie-Sue Orr, October 6, 1986 12:34:24 pm PDT
FIXBADPAGE
CEDAR 6.1 — FOR INTERNAL XEROX USE ONLY
FixBadPage
Willie-Sue Orr
© Copyright 1986 Xerox Corporation. All rights reserved.
Abstract: FixBadPage provides commands for coping with bad pages on Cedar disks.
Created by: Willie-Sue Orr
Maintained by: Willie-Sue Orr <Willie-Sue.pa>
Keywords: BadPages
XEROX  Xerox Corporation
   Palo Alto Research Center
   3333 Coyote Hill Road
   Palo Alto, California 94304

For Internal Xerox Use Only
FixBadPageImpl
Warning: Caution is strongly urged in using this code. If in any doubt, ask a wizard.
Provides several commands for dealing with known bad pages, or files known to have bad pages. If you do not know how to find out the pagenumber of the bad page (e. g., when you get an error window), you should ask a wizard.
All of the commands give feedback in the CommandTool typescript. There are load files for each.
% FixBadPage pageNum {driveNum}
If the machine has multiple drives, a drive number must be specified.
If the bad page is part of a file, the user will be prompted to determine whether the file should be destroyed, or if the user want to try to recover the data in the bad page, or cautiously try to recover the data in the bad page; the user has the option of quitting at this time.
If the cautious option is selected, the page replacement is done ONLY if the data in the bad page can be read without error; flaky pages can sometimes be read.
Once the data is (hopefully) recovered or the file is deleted, the page is put into the bad page table for the drive and the appropriate VAM is updated.
% RecoverBadPage pageNum {driveNum}
Like FixBadPage with (attempted) recovery of data selected.
% CautiouslyRecoverBadPage pageNum {driveNum}
Like FixBadPage with cautious recovery of data selected.
% DeleteBadPage pageNum {driveNum}
Like FixBadPage with deletion of file selected.
% DescribePage pageNum {driveNum}
Like FixBadPage with quit option selected.
The next two commands expect there to be a bad page in the file. If reading the file cannot find a bad page, the commands quits. This can happen with pages that are flaky.
% FixFile fileName
fileName can be on any logical volume, or a cached file; is it is a cached file, then you MUST include a version number, or you might not get the file you expect. FixFile will try to find a bad page in the file; if it does, it will ask the user what to do with the file.
% RecoverFile fileName
Like FixFile with (attempted) recovery of data selected.
% CautiouslyRecoverFile fileName
Like FixFile with cautious recovery of data selected.
% DeleteFile fileName
Like FixFile with deletion of file selected.
Information about the bad page table(s).
% ListBadPages {physicalVolume}
prints the bad page table for a physical volume, by subVolume (usually the same as logical volume), giving both logical and physical page numbers. If your machine has more than one physical volume, you must specify which one.
These last two commands were handy during debugging, and sort of interesting.
% ShowRunTable fileName
prints out the run table information for the file.
% RunTableFromFileID id da {logicalVolumeName}
If id and da describe a file for logicalVolumeName, the runtable for that file is printed. The logicalVolumeName parameter is needed if there is more than one logical volume.