Provided by:
sfs-server_0.8-0+pre20060720.1-1.1_i386
NAME
vidb - manually edit SFS user-authentication database file
SYNOPSIS
vidb [-w] [-R] {-S | -a [-f file] | [-e editor]} sfs-users-file
DESCRIPTION
vidb manually edits an SFS user-authentication file , acquiring locks
to prevent concurrent updates from overwriting each other. If sfsauthd
has been compiled with Sleepycat database (http://www.sleepycat.com/)
support, and the name of the file ends in .db/, vidb will consider the
user authentication file to be a database directory, and convert the
contents into regular ASCII text for editing. If the name of the file
ends in .db, vidb assumes the user authentication file is database file
(unless the pathname corresponds to an existing directory). Note that
database files (as opposed to directories) are required to be
read-only, and thus cannot be updated by vidb.
OPTIONS
vidb has the following options:
-a [-f file]
The -a option adds SFS user records in text form to a database.
The records are taken from standard input, or from file if speci‐
fied. Records for an existing user or group will replace the val‐
ues already in the database. Unlike vidb’s ordinary mode of opera‐
tion, -a does not add all records atomically. In the event of a
system crash, some but not all of the records may have been added
to the database. Simply re-running the same vidb command after a
crash is perfectly safe, however, since previously added entries
will just be overwritten (by themselves) the second time through.
For database files, because -a does not accumulate records into one
large transaction, it can be significantly more efficient than sim‐
ply adding the records in an editor, using vidb’s ordinary mode of
operation.
-e editor
Specifies the editor to use for editing the file. The default is
to use the command specified by the environment variable EDITOR.
If there is no environment variable and -e is not specified, vidb
uses vi.
-w One of the points of vidb is to avoid concurrent edits to the
database and the corresponding inconsistencies that might result.
Ordinarily, if the database is already being edited, vidb will just
exit with an error message. The -w flag tells vidb to wait until
it can acquire the lock on the database before launching the edi‐
tor.
-R Runs catastrophic recovery on the database environment. (For those
familiar with Sleepycat database software, this corresponds to the
-c flag of the db_recover utility, or the DB_RECOVER_FATAL flag of
the API.) Essentially, -R replays all of the database log records
present in the supporting files directory. You may need to use
this, for example, when restoring a database from backup tapes if
the log files were backed up more recently than the entire
database. The -R has no effect on flat text databases, or if the
-S has been specified. Warning: The authors have encountered bugs
in the catastrophic recovery code of at least some versions of the
Sleepycat database package. As a precaution, before attempting to
use -R, we strongly recommend salvaging whatever records possible
from the database file itself using vidb -S sfs-users-
file>saved_sfs_users. If, subsequently, the -R option corrupts the
database, you can at least salvage some of the records from the
saved_sfs_users file.
-S Attempt to salvage a database file with corrupt or lost logs by
dumping the contents of the database itself. Ordinarily, databases
use write-ahead logging. Before opening a database file, both vidb
and sfsauthd attempt to recover from any previous incomplete trans‐
actions using the log. The -S option opens and prints out the con‐
tents of a database without regard to the log files. This is use‐
ful if you have lost the log files or are worried that they are
corrupt, or if you wish to examine the contents of a database you
have read but not write permission to. Ordinarily, however, if you
wish to dump the contents of a database to standard output, use the
command vidb -e cat sfs-users-file.
dirsearch(1), newaid(1), rex(1), sfsagent(1), sfskey(1), ssu(1),
sfs_config(5), sfs_hosts(5), sfs_srp_params(5), sfs_users(5),
sfsauthd_config(5), sfscd_config(5), sfsrosd_config(5), sfsrwsd_con‐
fig(5), sfssd_config(5), sfs_environ(7), funmount(8), nfsmounter(8),
sfsauthd(8), sfscd(8), sfsrosd(8), sfsrwcd(8), sfsrwsd(8), sfssd(8)
The full documentation for SFS is maintained as a Texinfo manual. If
the info and SFS programs are properly installed at your site, the com‐
mand info SFS should give you access to the complete manual.
For updates, documentation, and software distribution, please see the
SFS website at http://www.fs.net/.
BUGS
vidb should really recreate any publicly-readable versions of user
authentication databases (either by parsing sfsauthd_config for
-pub=... options to Userfile directives or signaling sfsauthd). Cur‐
rently you must manually kill sfssd or sfsauthd for this to happen.
While vidb attempts to make the smallest number of changes to a
database, editing sessions that add or remove a large number of records
can potentially exhaust resources such as locks. Sites with large user
databases can tune the database by creating a file called DB_CONFIG in
the database directory. The specifics of the configuration file are
documented in the Sleepycat database documentation. As an example, if
performance is slow and you run out of locks, you can set the cache
size to 128MB and increase the number of locks with the following
DB_CONFIG file:
set_cachesize 0 134217728 1
set_lk_max_locks 50000
set_lk_max_objects 50000
When editing a database, vidb creates a temporary text file in the /tmp
directory. For huge databases, it is conceivable that /tmp does not
have enough space. If this happens, /tmp can be overridden with the
TMPDIR environment variable.
AUTHOR
sfsdev@redlab.lcs.mit.edu