From: david-sarah Date: Sun, 12 Dec 2010 19:55:22 +0000 (-0800) Subject: docs/configuration.rst: more formatting tweaks; which -> that. X-Git-Url: https://git.rkrishnan.org/simplejson/components/com_hotproperty/status?a=commitdiff_plain;h=dfd9c8a949cc801c6a3e81b31bbc9029af054cbd;p=tahoe-lafs%2Ftahoe-lafs.git docs/configuration.rst: more formatting tweaks; which -> that. --- diff --git a/docs/configuration.rst b/docs/configuration.rst index 1cde567b..c9b17609 100644 --- a/docs/configuration.rst +++ b/docs/configuration.rst @@ -23,10 +23,10 @@ This document contains a complete list of the config files that are examined by the client node, as well as the state files that you'll observe in its base directory. -The main file is named "``tahoe.cfg``", which is an ".INI"-style configuration +The main file is named "``tahoe.cfg``", and is an ".INI"-style configuration file (parsed by the Python stdlib 'ConfigParser' module: "``[name]``" section markers, lines with "``key.subkey: value``", rfc822-style continuations). There -are other files that contain information which does not easily fit into this +are also other files containing information that does not easily fit into this format. The "``tahoe create-node``" or "``tahoe create-client``" command will create an initial ``tahoe.cfg`` file for you. After creation, the node will never modify the ``tahoe.cfg`` file: all persistent state is put in other files. @@ -85,7 +85,7 @@ set the ``tub.location`` option described below. This controls where the ``/static`` portion of the URL space is served. The value is a directory name (``~username`` is allowed, and non-absolute names - are interpreted relative to the node's basedir) which can contain HTML + are interpreted relative to the node's basedir), which can contain HTML and other files. This can be used to serve a Javascript-based frontend to the Tahoe-LAFS node, or other services. @@ -182,7 +182,7 @@ set the ``tub.location`` option described below. ``log_gatherer.furl = (FURL, optional)`` - If provided, this contains a single FURL string which is used to contact + If provided, this contains a single FURL string that is used to contact a "log gatherer", which will be granted access to the logport. This can be used by centralized storage grids to gather operational logs in a single place. Note that when an old-style ``BASEDIR/log_gatherer.furl`` file @@ -242,7 +242,7 @@ set the ``tub.location`` option described below. 10GB available for the upload to complete. The default value is the ``tmp`` directory in the node's base directory - (i.e. ``NODEDIR/tmp``), but it can be placed elsewhere. This directory is + (i.e. ``BASEDIR/tmp``), but it can be placed elsewhere. This directory is used for files that usually (on a Unix system) go into ``/tmp``. The string will be interpreted relative to the node's base directory. @@ -290,17 +290,17 @@ Client Configuration equivalent to simple replication (uploading ``N`` copies of the file). These values control the tradeoff between storage overhead, performance, - and reliability. To a first approximation, a 1MB file will use (1MB*``N``/``k``) + and reliability. To a first approximation, a 1MB file will use (1MB * ``N``/``k``) of backend storage space (the actual value will be a bit more, because of other forms of overhead). Up to ``N``-``k`` shares can be lost before the file becomes unrecoverable, so assuming there are at least ``N`` servers, up to - N-k servers can be offline without losing the file. So large ``N``/``k`` + ``N``-``k`` servers can be offline without losing the file. So large ``N``/``k`` ratios are more reliable, and small ``N``/``k`` ratios use less disk space. Clearly, ``k`` must never be smaller than ``N``. Large values of ``N`` will slow down upload operations slightly, since more servers must be involved, and will slightly increase storage overhead due - to the hash trees that are created. Large values of k will cause + to the hash trees that are created. Large values of ``k`` will cause downloads to be marginally slower, because more servers must be involved. ``N`` cannot be larger than 256, because of the 8-bit erasure-coding algorithm that Tahoe-LAFS uses. @@ -336,7 +336,7 @@ Storage Server Configuration If ``True``, the node will run a storage server but will not accept any shares, making it effectively read-only. Use this for storage servers - which are being decommissioned: the ``storage/`` directory could be mounted + that are being decommissioned: the ``storage/`` directory could be mounted read-only, while shares are moved to other servers. Note that this currently only affects immutable shares. Mutable shares (used for directories) will be written and modified anyway. See ticket `#390 @@ -346,7 +346,7 @@ Storage Server Configuration ``reserved_space = (str, optional)`` If provided, this value defines how much disk space is reserved: the - storage server will not accept any share which causes the amount of free + storage server will not accept any share that causes the amount of free disk space to drop below this value. (The free space is measured by a call to statvfs(2) on Unix, or GetDiskFreeSpaceEx on Windows, and is the space available to the user account under which the storage server runs.) @@ -386,9 +386,9 @@ service. If ``True``, the node will run a helper (see ``_ for details). The helper's contact FURL will be placed in ``private/helper.furl``, from - which it can be copied to any clients which wish to use it. Clearly nodes + which it can be copied to any clients that wish to use it. Clearly nodes should not both run a helper and attempt to use one: do not create - ``helper.furl`` and also define ``[helper] enabled`` in the same node. + ``helper.furl`` and also define ``[helper]enabled`` in the same node. The default is ``False``.