|  | 
 NAME     
 |  |  |  | fossil, flchk, flfmt – archival file server 
 | 
 SYNOPSIS     
 |  |  |  | fossil/fossil [ −Dt ] [ −c cmd ]... [ −f file ] [ −m free-memory-percent
    ] 
    
    
    fossil/flchk [ −f ] [ −c ncache ] [ −h host ] file 
    
    
    fossil/flfmt [ −y ] [ −b blocksize ] [ −h host ] [ −l label ]
    [ −v score ] file 
    
    
    fossil/conf [ −w ] file [ config ] 
    
    
    fossil/last file 
 | 
 DESCRIPTION     
 |  |  |  | Fossil is the main file system for Plan 9. Unlike the Plan 9 file
    servers of old, fossil is a collection of user-space programs
    that run on a standard Plan 9 kernel. The name of the main fossil
    file server at Murray Hill is pie. The Plan 9 distribution file
    server, sources, is also a fossil server. 
    
    
    Fossil is structured as a magnetic disk write buffer optionally
    backed by a Venti server for archival storage. It serves the Plan
    9 protocol via TCP. A fossil file server conventionally presents
    three trees in the root directory of each file system: active,
    archive, and snapshot. /active is the root of a conventional file
    system whose blocks are stored
    in a disk file. In a typical configuration, the file server periodically
    marks the entire file system copy-on-write, effectively taking
    a snapshot of the file system at that moment. This snapshot is
    made available in a name created from the date and time of the
    snapshot: /snapshot/yyyy/mmdd/hhmm where yyyy is the full year,
    mm is the month number,
    dd is the day number, hh is the hour, and mm is the minute. The
    snapshots in /snapshot are ephemeral: eventually they are deleted
    to reclaim the disk space they occupy. Long-lasting snapshots
    stored on a Venti server are kept in /archive and also named from
    the date (though not the time) of the snapshot: /archive/yyyy/mmdds,
    where
    yyyy, mm, and dd are year, month, and day as before, and s is
    a sequence number if more than one archival snapshot is done in
    a day. For the first snapshot, s is null. For the subsequent snapshots,
    s is .1, .2, .3, etc. The root of the main file system that is
    frozen for the first archival snapshot of December 15, 2002 will
    be named
    /archive/2002/1215/. 
    
    
    The attach name used in mount (see bind(1), bind(2) and attach(5))
    selects a file system to be served and optionally a subtree, in
    the format fs[/dir]. An empty attach name selects main/active.
    
    
    
    Fossil normally requires all users except none to provide authentication
    tickets on each attach(5). To keep just anyone from connecting,
    none is only allowed to attach after another user has successfully
    attached on the same connection. The other user effectively acts
    as a chaperone for none. Authentication can be disabled using
    the −A flag to open
    or srv (see fossilcons(8)). 
    
    
    The groups called noworld and write are special on the file server.
    Any user belonging to noworld has attenuated access privileges.
    Specifically, when checking such a user’s access to files, the
    file’s permission bits are first ANDed with 0770 for normal files
    and 0771 for directories. The effect is to deny world access permissions
    to noworld
    users, except when walking into directories. If the write group
    exists, then the file system appears read-only to users not in
    the group. This is used to make the Plan 9 distribution file server
    (sources.cs.bell-labs.com) readable by the world but writable
    only to the developers. 
    
    
    Fossil starts a new instance of the fossil file server. It is
    configured mainly through console commands, documented in fossilcons(8).
    
    
    
    The options are: −D     Toggle the debugging flag, which is initially off. When the
    flag is set, information about authentication and all protocol
    messages are written to standard error.
 −t     Start a file server console on /dev/cons. If this option is
    given, fossil does not fork itself into the background.
 −c cmdExecute the console command cmd. This option may be repeated
    to give multiple commands. Typically the only commands given on
    the command line are “. file,” which executes a file containing
    commands, and “srv −pcons,” which starts a file server console
    on /srv/cons. See fossilcons(8) for more information.
    −f file   Read and execute console commands stored in the Fossil
    disk file. Conf (q.v.) reads and writes the command set stored
    in the disk.
 −m     Allocate free-memory-percent percent of the available free RAM
    for buffers. This overrides all other memory sizing parameters,
    notably the −c option to open. 30% is a reasonable choice. 
    
    
    Flchk checks the fossil file system stored in file for inconsistencies.
    Flchk is deprecated in favor of the console check command (see
    fossilcons(8)). Flchk prints fossil console commands that may
    be executed to take care of bad pointers (clrp), bad entries (clre),
    bad directory entries (clri), unreachable blocks (bfree). Console
    commands are
    interspersed with more detailed commentary on the file system.
    The commands are distinguished by being prefixed with sharp signs.
    Note that all proposed fixes are rather drastic: offending pieces
    of file system are simply chopped off. 
    
    
    Flchk does not modify the file system, so it is safe to run concurrently
    with fossil, though in this case the list of unreachable blocks
    and any inconsistencies involving the active file system should
    be taken with a grain of salt. 
    
    
    The options are:
 −f     Fast mode. By default, flchk checks the entire file system image
    for consistency, which includes all the archives to Venti and
    can take a very long time. In fast mode, flchk avoids walking
    in Venti blocks whenever possible.
 −c ncache
 
 −h hostUse host as the Venti server. 
    
    
    Flfmt prepares file as a new fossil file system. The file system
    is initialized with three empty directories active, archive, and
    snapshot, as described above. The options are:|  |  |  | |  |  |  | Keep a cache of ncache (by default, 1000) file system blocks in
            memory during the check. 
 | 
 | 
 −y       Yes mode. By default, flfmt will prompt for confirmation before
    formatting a file that already contains a fossil file system,
    and before formatting a file that is not served directly by a
    kernel device. If the −y flag is given, no such checks are made.
 −b blocksizeSet the file system block size (by default, 8192).
 −h host    Use host as the Venti server.
 −l label    Set the textual label on the file system to label. The
    label is only a comment.
 −v score    Initialize the file system using the vac file system stored
    on Venti at score. The score should have been generated by fossil
    rather than by vac(1), so that the appropriate snapshot metadata
    is present. 
    
    
    Conf reads or writes the configuration branded on the Fossil disk
    file. By default, it reads the configuration from the disk and
    prints it to standard output. If the −w flag is given, conf reads
    a new configuration from config (or else from standard input)
    and writes it to the disk. Inside the configuration file, the
    argument * may be used to stand in for the name
    of the disk holding the configuration. The Plan 9 kernel boot
    process runs “fossil −f disk” to start a Fossil file server. The
    disk is just a convenient place to store configuration information.
    
    
    
    Last prints the vac score that resulted after the most recent
    archival snapshot of the fossil in file.
 
 | 
 EXAMPLES     
 |  |  |  | Place the root of the archive file system on /n/dump and show
    the modified times of the MIPS C compiler over all dumps in December
    2002: 
 To get only one line of output for each version of the compiler:|  |  |  | 9fs dump ls −l /n/dump/2002/12*/mips/bin/vc
 
 | 
 
 Initialize a new file system, start the server with permission
    checking turned off, create a users file, and mount the server:|  |  |  | ls −lp /n/dump/2002/12*/mips/bin/vc | uniq 
 | 
 
 See the discussion of the users and uname commands in fossilcons(8)
    for more about the user table. 
    
    
    Perhaps because the disk has been corrupted or replaced, format
    a new file system using the last archive score printed on the
    console:|  |  |  | fossil/flfmt /dev/sdC0/fossil fossil/conf −w /dev/sdC0/fossil <<EOF
 fsys main config
 fsys main open −AWP
 fsys main
 create /active/adm adm sys d775
 create /active/adm/users adm sys 664
 users −w
 srv −p fscons
 srv fossil
 EOF
 fossil/fossil −f /dev/sdC0/fossil
 mount /srv/fossil /n/fossil
 
 | 
 
 Note that while /snapshot will be lost, /active and /archive will
    be restored to their contents at the time of the last archival
    snapshot. 
    
    
    Blindly accept the changes prescribed by flchk (not recommended):|  |  |  | fossil/flfmt −v b9b3...5559 /dev/sdC0/fossil 
 | 
 
 A better strategy is to vet the output, filter out any suggestions
    you’re not comfortable with, and then use the sed command to prepare
    the script.|  |  |  | fossil/flchk /dev/sdC0/fossil | sed −n 's/^# //p' >>/srv/fscons 
 | 
 
 | 
 SOURCE     
 SEE ALSO    
 BUGS     
 |  |  |  | It is possible that the disk format (but not the Venti format)
    will change in the future, to make the disk a full cache rather
    than just a write buffer. Changing to the new format will require
    reformatting the disk as in the example above, but note that this
    will preserve most of the file system (all but /snapshot) with
    little effort. 
    
    
    The −m option currently assumes a block size of 8K bytes, and
    a single file system per fossil instance. 
 | 
 |  |