Provided by: inn2-lfs_2.5.0-1ubuntu1_i386 bug

NAME

       storage.conf - Configuration file for storage manager

DESCRIPTION

       The file pathetc/storage.conf contains the rules to be used in
       assigning articles to different storage methods.  These rules determine
       where incoming articles will be stored.

       The storage manager is a unified interface between INN and a variety of
       different storage methods, allowing the news administrator to choose
       between different storage methods with different trade-offs (or even
       use several at the same time for different newsgroups, or articles of
       different sizes).  The rest of INN need not care what type of storage
       method was used for a given article; the storage manager will figure
       this out automatically when that article is retrieved via the storage
       API.  Note that you may also want to see the options provided in
       inn.conf(5) regarding article storage.

       The storage.conf file consists of a series of storage method entries.
       Blank lines and lines beginning with a number sign ("#") are ignored.
       The maximum number of characters in each line is 255.  The order of
       entries in this file is important, see below.

       Each entry specifies a storage method and a set of rules.  Articles
       which match all of the rules of a storage method entry will be stored
       using that storage method; if an article matches multiple storage
       method entries, the first one will be used.  Each entry is formatted as
       follows:

           method <methodname> {
               class: <storage_class>
               newsgroups: <wildmat>
               size: <minsize>[,<maxsize>]
               expires: <mintime>[,<maxtime>]
               options: <options>
               exactmatch: <bool>
           }

       If spaces or tabs are included in a value, that value must be enclosed
       in double quotes ("").  If either a number sign ("#") or a double quote
       are meant to be included verbatim in a value, they should be escaped
       with "\".

       <methodname> is the name of a storage method to use for articles which
       match the rules of this entry.  The currently available storage methods
       are:

           cnfs
           timecaf
           timehash
           tradspool
           trash

       See the "STORAGE METHODS" section below for more details.

       The meanings of the keys in each storage method entry are as follows:

       class: <storage_class>
           An identifier for this storage method entry.  <storage_class>
           should be a number between 0 and 255.  It should be unique across
           all of the entries in this file.  It is mainly used for specifying
           expiration times by storage class as described in expire.ctl(5);
           "timehash" and "timecaf" will also set the top-level directory in
           which articles accepted by this storage class are stored.  The
           assignment of a particular number to a storage class is arbitrary
           but permanent (since it is used in storage tokens).  Storage
           classes can be for instance numbered sequentially in storage.conf.

       newsgroups: <wildmat>
           What newsgroups are stored using this storage method.  <wildmat> is
           a uwildmat(3) pattern which is matched against the newsgroups an
           article is posted to.  If storeonxref in inn.conf is true, this
           pattern will be matched against the newsgroup names in the Xref:
           header; otherwise, it will be matched against the newsgroup names
           in the Newsgroups: header (see inn.conf(5) for discussion of the
           differences between these possibilities).  Poison wildmat
           expressions (expressions starting with "@") are allowed and can be
           used to exclude certain group patterns:  articles crossposted to
           poisoned newsgroups will not be stored using this storage method.
           The <wildmat> pattern is matched in order.

           There is no default newsgroups pattern; if an entry should match
           all newsgroups, use an explicit "newsgroups: *".

       size: <minsize>[,<maxsize>]
           A range of article sizes (in bytes) which should be stored using
           this storage method.  If <maxsize> is 0 or not given, the upper
           size of articles is limited only by maxartsize in inn.conf.  The
           size: field is optional and may be omitted entirely if you want
           articles of any size to be stored in this storage method (if, of
           course, these articles fulfill all the other requirements of this
           storage method entry).  By default, <minsize> is set to 0.

       expires: <mintime>[,<maxtime>]
           A range of article expiration times which should be stored using
           this storage method.  Be careful; this is less useful than it may
           appear at first.  This is based only on the Expires: header of the
           article, not on any local expiration policies or anything in
           expire.ctl!  If <mintime> is non-zero, then this entry will not
           match any article without an Expires: header.  This key is
           therefore only really useful for assigning articles with requested
           longer expire times to a separate storage method.  Articles only
           match if the time until expiration (that is to say, the amount of
           time into the future that the Expires: header of the article
           requests that it remain around) falls in the interval specified by
           <mintime> and <maxtime>.

           The format of these parameters is "0d0h0m0s" (days, hours, minutes,
           and seconds into the future).  If <maxtime> is "0s" or is not
           specified, there is no upper bound on expire times falling into
           this entry (note that this key has no effect on when the article
           will actually be expired, but only on whether or not the article
           will be stored using this storage method).  This field is also
           optional and may be omitted entirely if you do not want to store
           articles according to their Expires: header, if any.

           A <mintime> value greater than "0s" implies that this storage
           method won’t match any article without an Expires: header.

       options: <options>
           This key is for passing special options to storage methods that
           require them (currently only "cnfs").  See the "STORAGE METHODS"
           section below for a description of its use.

       exactmatch: <bool>
           If this key is set to true, all the newsgroups in the Newsgroups:
           header of incoming articles will be examined to see if they match
           newsgroups patterns.  (Normally, any non-zero number of matching
           newsgroups is sufficient, provided no newsgroup matches a poison
           wildmat as described above.)  This is a boolean value; "true",
           "yes" and "on" are usable to enable this key.  The case of these
           values is not significant.  The default is false.

       If an article matches all of the constraints of an entry, it is stored
       via that storage method and is associated with that <storage_class>.
       This file is scanned in order and the first matching entry is used to
       store the article.

       If an article does not match any entry, either by being posted to a
       newsgroup which does not match any of the <wildmat> patterns or by
       being outside the size and expires ranges of all entries whose
       newsgroups pattern it does match, the article is not stored and is
       rejected by innd.  When this happens, the error message:

           cant store article: no matching entry in storage.conf

       is logged to syslog.  If you want to silently drop articles matching
       certain newsgroup patterns or size or expires ranges, assign them to
       the "trash" storage method rather than having them not match any
       storage method entry.

STORAGE METHODS

       Currently, there are five storage methods available.  Each method has
       its pros and cons; you can choose any mixture of them as is suitable
       for your environment.  Note that each method has an attribute
       EXPENSIVESTAT which indicates whether checking the existence of an
       article is expensive or not.  This is used to run expireover(8).

       cnfs
           The "cnfs" storage method stores articles in large cyclic buffers
           (CNFS stands for Cyclic News File System).  Articles are stored in
           CNFS buffers in arrival order, and when the buffer fills, it wraps
           around to the beginning and stores new articles over the top of the
           oldest articles in the buffer. The expire time of articles stored
           in CNFS buffers is therefore entirely determined by how long it
           takes the buffer to wrap around, which depends on how quickly data
           is being stored in it.  (This method is therefore said to have
           self-expire functionality.)  EXPENSIVESTAT is false for this
           method.

           CNFS has its own configuration file, cycbuff.conf, which describes
           some subtleties to the basic description given above.  Storage
           method entries for the "cnfs" storage method must have an options:
           field specifying the metacycbuff into which articles matching that
           entry should be stored; see cycbuff.conf(5) for details on
           metacycbuffs.

           Advantages:  By far the fastest of all storage methods (except for
           "trash"), since it eliminates the overhead of dealing with a file
           system and creating new files.  Unlike all other storage methods,
           it does not require manual article expiration.  With CNFS, the
           server will never throttle itself due to a full spool disk, and
           groups are restricted to just the buffer files given so that they
           can never use more than the amount of disk space allocated to them.

           Disadvantages:  Article retention times are more difficult to
           control because old articles are overwritten automatically.
           Attacks on Usenet, such as flooding or massive amounts of spam, can
           result in wanted articles expiring much faster than intended (with
           no warning).

       timecaf
           This method stores multiple articles in one file, whose name is
           based on the article’s arrival time and the storage class.  The
           file name will be:

               <patharticles>/timecaf-nn/bb/aacc.CF

           where "nn" is the hexadecimal value of <storage_class>, "bb" and
           "aacc" are the hexadecimal components of the arrival time, and "CF"
           is a hardcoded extension.  (The arrival time, in seconds since the
           epoch, is converted to hexadecimal and interpreted as 0xaabbccdd,
           with "aa", "bb", and "cc" used to build the path.)  This method
           does not have self-expire functionality (meaning expire has to run
           periodically to delete old articles).  EXPENSIVESTAT is false for
           this method.

           Advantages:  It is roughly four times faster than "timehash" for
           article writes, since much of the file system overhead is bypassed,
           while still retaining the same fine control over article retention
           time.

           Disadvantages:  Using this method means giving up all but the most
           careful manually fiddling with the article spool; in this aspect,
           it looks like "cnfs".  As one of the newer and least widely used
           storage types, "timecaf" has not been as thoroughly tested as the
           other methods.

       timehash
           This method is very similar to "timecaf" except that each article
           is stored in a separate file.  The name of the file for a given
           article will be:

               <patharticles>/time-nn/bb/cc/yyyy-aadd

           where "nn" is the hexadecimal value of <storage_class>, "yyyy" is a
           hexadecimal sequence number, and "bb", "cc", and "aadd" are
           components of the arrival time in hexadecimal (the arrival time is
           interpreted as documented above under "timecaf").  This method does
           not have self-expire functionality.  EXPENSIVESTAT is true for this
           method.

           Advantages:  Heavy traffic groups do not cause bottlenecks, and a
           fine control of article retention time is still possible.

           Disadvantages:  The ability to easily find all articles in a given
           newsgroup and manually fiddle with the article spool is lost, and
           INN still suffers from speed degradation due to file system
           overhead (creating and deleting individual files is a slow
           operation).

       tradspool
           Traditional spool, or "tradspool", is the traditional news article
           storage format.  Each article is stored in an individual text file
           named:

               <patharticles>/news/group/name/nnnnn

           where "news/group/name" is the name of the newsgroup to which the
           article was posted with each period changed to a slash, and "nnnnn"
           is the sequence number of the article in that newsgroup.  For
           crossposted articles, the article is linked into each newsgroup to
           which it is crossposted (using either hard or symbolic links).
           This is the way versions of INN prior to 2.0 stored all articles,
           as well as being the article storage format used by C News and
           earlier news systems.  This method does not have self-expire
           functionality.  EXPENSIVESTAT is true for this method.

           Advantages:  It is widely used and well-understood; it can read
           article spools written by older versions of INN and it is
           compatible with all third-party INN add-ons.  This storage
           mechanism provides easy and direct access to the articles stored on
           the server and makes writing programs that fiddle with the news
           spool very easy, and gives fine control over article retention
           times.

           Disadvantages:  It takes a very fast file system and I/O system to
           keep up with current Usenet traffic volumes due to file system
           overhead.  Groups with heavy traffic tend to create a bottleneck
           because of inefficiencies in storing large numbers of article files
           in a single directory.  It requires a nightly expire program to
           delete old articles out of the news spool, a process that can slow
           down the server for several hours or more.

       trash
           This method silently discards all articles stored in it.  Its only
           real uses are for testing and for silently discarding articles
           matching a particular storage method entry (for whatever reason).
           Articles stored in this method take up no disk space and can never
           be retrieved, so this method has self-expire functionality of a
           sort.  EXPENSIVESTAT is false for this method.

EXAMPLES

       The following sample storage.conf file would store all articles posted
       to alt.binaries.* in the "BINARIES" CNFS metacycbuff, all articles over
       roughly 50 KB in any other hierarchy in the "LARGE" CNFS metacycbuff,
       all other articles in alt.* in one timehash class, and all other
       articles in any newsgroups in a second timehash class, except for the
       internal.* hierarchy which is stored in traditional spool format.

           method tradspool {
               class: 1
               newsgroups: internal.*
           }
           method cnfs {
               class: 2
               newsgroups: alt.binaries.*
               options: BINARIES
           }
           method cnfs {
               class: 3
               newsgroups: *
               size: 50000
               options: LARGE
           }
           method timehash {
               class: 4
               newsgroups: alt.*
           }
           method timehash {
               class: 5
               newsgroups: *
           }

       Notice that the last storage method entry will catch everything.  This
       is a good habit to get into; make sure that you have at least one
       catch-all entry just in case something you did not expect falls through
       the cracks.  Notice also that the special rule for the internal.*
       hierarchy is first, so it will catch even articles crossposted to
       alt.binaries.* or over 50 KB in size.

       As for poison wildmat expressions, if you have for instance an article
       crossposted between misc.foo and misc.bar, the pattern:

           misc.*,!misc.bar

       will match that article whereas the pattern:

           misc.*,@misc.bar

       will not match that article.  An article posted only to misc.bar will
       fail to match either pattern.

       Usually, high-volume groups and groups whose articles do not need to be
       kept around very long (binaries groups, *.jobs*, news.lists.filters,
       etc.) are stored in CNFS buffers.  Use the other methods (or CNFS
       buffers again) for everything else.  However, it is as often as not
       most convenient to keep in "tradspool" special hierarchies like local
       hierarchies and hierarchies that should never expire or through the
       spool of which you need to go manually.

HISTORY

       Written by Katsuhiro Kondou <kondou@nec.co.jp> for InterNetNews.
       Rewritten into POD by Julien Elie.

       $Id: storage.conf.pod 8357 2009-02-27 17:56:00Z iulius $

SEE ALSO

       cycbuff.conf(5), expire.ctl(5), expireover(8), inn.conf(5), innd(8),
       uwildmat(3).