rmsck - check RMSfiles for consistency
rmsck[ -afeynsqxk ] [-b dbname] [-v n] [-t n] file [file...]
Rmsck examines C/Base RMSfiles and checks their contents for consistency.
Rmsck makes a detailed examination of the data stored in the RMSfiles,
and will repair (if given permission) any errors it finds.
The following flags are recognized by rmsck:
-y Answer Yes to all questions.
-n Answer No to all questions.
-s Answer Skip to all questions.
-q Answer Quit to all questions.
If rmsck finds an error, it describes the error and then asks for
the
action to be taken. For example, if there were a record that was
in the
RMSfile, but for some reason the record keys were not in the RMS
index
file, rmsck would announce:
NUMBER OF KEYS IN INDEX 0 NOT EQUAL TO
NUMBER OF ACTIVE RECORDS
REBUILD THIS INDEX?
When asked a question, you may respond Yes, No, Skip, or Quit. Answering
Yes performs the action; answering No does not, and continues processing
the RMS-file; answering Skip stops processing the current RMSfile
and
starts checking the next RMSfile; and answering Quit terminates
rmsck.
You may specify the answer to all questions in advance by using
the -y,
-n, -s, or -q command line flag. For example, -n will check all
the
RMSfiles, but not make any changes.
-b dbname
Check all RMSfiles in database dbname.]
-a Check all RMSfiles in database catalog.]
These two command line flags simplify the selection of RMSfiles.
The -b flag lets you name a database to be checked; all the
RMSfiles in that database are checked by rmsck. The -a flag
checks all RMSfiles in all databases. These two flags use the
database catalog to find the RMSfiles to be scanned. Rmsck first
checks the database catalog itself for consistency when these two
flags are used.
-e Test only that RMSfiles exist. This flag is used in conjunction
with the -b or -a flag to confirm that the RMSfiles named in the
database catalog actually exist without being required to also
check the contents of each RMSfile for consistency.
-v n Set message level to n (0-3). Rmsck issues status messages
while
it is running. You can modify the message level and thus change
the number of status messages that are given. When rmsck starts,
the message level is 1, and each RMSfile name is printed while it
is processed. A message level of 0 prints no status messages.
Message levels 2 and 3 give more description of the progress of
rmsck.
-t n Use n byte table when rebuilding index. See the description
of
this flag in the OPERATION section below.
-x Rebuild index using external sort. See the description of this
flag in the OPERATION section below.
-k Confirm that index key values match record contents. See the
description of this flag in the OPERATION section below.
OPERATION
Rmsck makes several passes over each RMSfile. To understand the
process
rmsck follows, a detailed understanding of the structure of RMSfiles
is
needed. See Section 4.2, "Data File Organization", in the C/Base
Utilities manual for a discussion of the internal RMSfile organization.
The following discussion is not necessary to successfully run rmsck,
but
will let the curious reader understand its operation.
Pass 1 examines the status of each data record and builds a map
of all
the active, deleted, and unused records.
Pass 2 examines the deleted record list and confirms that the list
points
to only deleted records and that all deleted records are included
in the
list. This pass rebuilds the deleted record list if necessary.
Pass 3 examines the RMS index file. It scans each index in the RMS
index
file and checks that the index keys are in ascending order, that
each
active record is represented in the index exactly once, and that
the
index page connectivity is correct. If the -k flag is used, rmsck
will
read the record referenced by each index entry, and confirm that
the
key values in the index entry are also in the fetched record. Since
this will significantly slow the operation of rmsck, this procedure
is
optional. Rmsck remembers which indexes, if any, are in error, and
they are corrected in pass 5.
Pass 4 checks the list of deleted index pages and rebuilds the list
if
necessary.
Pass 5 is only run if there were errors in the RMS index file. This
pass
rebuilds either the entire RMS index file, or if only a single index
in
the file is corrupted, it will rebuild just that index.
When rebuilding an index, rmsck reads each data record, and builds
a table
in memory to hold the key values. When the table is filled, it is
sorted,
and then the keys are written (in order) to the RMS index file.
If all
the record keys will not fit in the table in memory, then this process
is repeated until all the records have been read.
Filling the table and writing its sorted contents into the index
is called
a batch. Rmsck uses a custom version of RMS that efficiently adds
record
keys when they are in ascending order, and there are not other record
keys already in the index. Rmsck may run slower if many batches
are
necessary to process one index, as each batch must be merged into
the
batches already contained in the index.
There are two solutions available for this. By default, rmsck allocates
a table less than 32K bytes. The -t flag lets you set a much larger
table
size, thus reducing the number of batches necessary. Because of
processor
restrictions, you cannot increase the batch size on Intel 8086 and
80286
processors.
The second solution is to use the -x flag. This does not use the
internal
memory table, but instead creates a text file containing the record
keys,
uses an external sort program to sort all the keys simultaneously,
and
then adds all the record keys in one batch.
Neither of these command line flags is required. Rmsck will always
work
properly without them. In fact, rmsck will automatically select
the -x
flag if more than 10 batches are necessary to rebuild an index.
Using
these flags will speed up rmsck when dealing with very large RMSfiles.
When rmsck has completed examining all the RMSfiles, it displays
a total
of the number of files with errors. If there are any files with
errors,
the program also exits with a non-zero status.
rbldidx(C-1).
DATA FILE ERROR MESSAGES
DATA RECORD n HAS INVALID STATUS
This error normally only occurs when an RMSfile and an RMS data
dictionary are out of sync; for example, by copying the dictionary
of one RMSfile on top of the dictionary for a different file.
Before fixing records, check that the file and dictionary belong
together.
ERROR READING DATA RECORD n
This error is displayed when there is an I/O error reading an
RMSfile.
ERROR WRITING DATA RECORD n
This error is displayed when there is an I/O error writing an
RMSfile.
PREMATURE END OF FILE, RECORD n
While reading the records sequentially, the end of the RMSfile
was reached before all the records (according to the dictionary)
were read.
FILE LONGER THAN EXPECTED
While reading the records sequentially, the end of the RMSfile
was NOT reached after reading the last record (according to the
dictionary).
NUMBER OF DELETED RECORDS NOT EQUAL TO NUMBER OF RECORDS
IN DELETED RECORD LIST
The deleted record list is incorrect and must be rebuilt.
ACTIVE OR UNUSED RECORD IN DELETED RECORD LIST
The deleted record list includes a record that has not been
deleted. The deleted record list must be rebuilt.
FILE IS READ ONLY AND CANNOT BE FIXED
You do not have write permission for either the RMSfile or the
RMS index file. No changes can be made. You can continue to scan
this RMSfile for errors, but no errors can be corrected.
CANNOT LOCK DATA FILE; FILE SKIPPED
Someone else is using the RMSfile, so it is unsafe to modify the
file. The RMSfile is checked only when it is possible to modify
it.
INDEX FILE ERROR MESSAGES
ERROR WRITING INDEX PAGE n
This error is displayed when there is an I/O error writing the
RMS index file.
KEYS OUT OF ORDER
This message is displayed, along with the incorrect values, when
the keys in the index are not in ascending order. The index must
be rebuilt.
NUMBER OF KEYS IN INDEX n NOT EQUAL TO NUMBER OF ACTIVE RECORDS
There are either too many or too few index entries in an index.
The index must be rebuilt.
INDEX FILE HAS INVALID LENGTH
The RMS index file is not an exact multiple of the size of an index
page. The RMS index file must be rebuilt.
INVALID PAGE NUMBER n IN INDEX
Each index page has pointers to other index pages in the index.
An out of range index page number has been found. The index must
be rebuilt.
INDEX HAS CROSS LINKS; PAGE n
An index page is referenced by two or more other index pages.
Each index page should be referenced exactly once. The index must
be rebuilt.
NUMBER OF DELETED INDEX PAGES NOT EQUAL TO NUMBER OF PAGES
IN DELETED INDEX
PAGE LIST
The deleted index page list is incorrect and must be rebuilt.
STRANGE INDEX PAGE FORMAT
Rmsck cannot decipher the contents of an index page. The index
must be rebuilt.
INVALID RECORD NUMBER n IN INDEX
Each key value in an index contains a record number. Some key
contains an illegal record number. The index must be rebuilt.
INCORRECT KEY VALUE FOR RECORD NUMBER n IN INDEX
The -k flag has been used, and the record contents does not match
the key value in the index. The index must be rebuilt.
INDEX ENTRY POINTS TO DELETED RECORD NUMBER n
An index key value contains the record number of a deleted record.
The index must be rebuilt.
TWO INDEX ENTRIES POINT TO RECORD NUMBER n
A data record is referenced by two different key values in the
same index. The index must be rebuilt.