1 .. -*- coding: utf-8-with-signature -*-
3 =============================
4 Configuring a Tahoe-LAFS node
5 =============================
8 2. `Overall Node Configuration`_
9 3. `Client Configuration`_
10 4. `Storage Server Configuration`_
11 5. `Frontend Configuration`_
12 6. `Running A Helper`_
13 7. `Running An Introducer`_
14 8. `Other Files in BASEDIR`_
18 A Tahoe-LAFS node is configured by writing to files in its base directory.
19 These files are read by the node when it starts, so each time you change
20 them, you need to restart the node.
22 The node also writes state to its base directory, so it will create files on
25 This document contains a complete list of the config files that are examined
26 by the client node, as well as the state files that you'll observe in its
29 The main file is named "``tahoe.cfg``", and is an ".INI"-style configuration
30 file (parsed by the Python stdlib 'ConfigParser' module: "``[name]``" section
31 markers, lines with "``key.subkey: value``", rfc822-style
32 continuations). There are also other files containing information that does
33 not easily fit into this format. The "``tahoe create-node``" or "``tahoe
34 create-client``" command will create an initial ``tahoe.cfg`` file for
35 you. After creation, the node will never modify the ``tahoe.cfg`` file: all
36 persistent state is put in other files.
38 The item descriptions below use the following types:
42 one of (True, yes, on, 1, False, off, no, 0), case-insensitive
46 a Twisted listening-port specification string, like "``tcp:80``" or
47 "``tcp:3456:interface=127.0.0.1``". For a full description of the format,
48 see `the Twisted strports documentation
49 <https://twistedmatrix.com/documents/current/api/twisted.application.strports.html>`_.
50 Please note, if interface= is not specified, Tahoe-LAFS will attempt to
51 bind the port specified on all interfaces.
55 a Foolscap endpoint identifier, like
56 ``pb://soklj4y7eok5c3xkmjeqpw@192.168.69.247:44801/eqpwqtzm``
62 A node can be a client/server, an introducer, a statistics gatherer, or a
65 Client/server nodes provide one or more of the following services:
74 A client/server that provides storage service (i.e. storing shares for
75 clients) is called a "storage server". If it provides any of the other
76 services, it is a "storage client" (a node can be both a storage server and a
77 storage client). A client/server node that provides web-API service is called
81 Overall Node Configuration
82 ==========================
84 This section controls the network behavior of the node overall: which ports
85 and IP addresses are used, when connections are timed out, etc. This
86 configuration applies to all node types and is independent of the services
87 that the node is offering.
89 If your node is behind a firewall or NAT device and you want other clients to
90 connect to it, you'll need to open a port in the firewall or NAT, and specify
91 that port number in the tub.port option. If behind a NAT, you *may* need to
92 set the ``tub.location`` option described below.
96 ``nickname = (UTF-8 string, optional)``
98 This value will be displayed in management tools as this node's
99 "nickname". If not provided, the nickname will be set to "<unspecified>".
100 This string shall be a UTF-8 encoded Unicode string.
102 ``web.port = (strports string, optional)``
104 This controls where the node's web server should listen, providing node
105 status and, if the node is a client/server, providing web-API service as
106 defined in `webapi.rst <frontends/webapi.rst>_`.
108 This file contains a Twisted "strports" specification such as "``3456``"
109 or "``tcp:3456:interface=127.0.0.1``". The "``tahoe create-node``" or
110 "``tahoe create-client``" commands set the ``web.port`` to
111 "``tcp:3456:interface=127.0.0.1``" by default; this is overridable by the
112 ``--webport`` option. You can make it use SSL by writing
113 "``ssl:3456:privateKey=mykey.pem:certKey=cert.pem``" instead.
115 If this is not provided, the node will not run a web server.
117 ``web.static = (string, optional)``
119 This controls where the ``/static`` portion of the URL space is
120 served. The value is a directory name (``~username`` is allowed, and
121 non-absolute names are interpreted relative to the node's basedir), which
122 can contain HTML and other files. This can be used to serve a
123 Javascript-based frontend to the Tahoe-LAFS node, or other services.
125 The default value is "``public_html``", which will serve
126 ``BASEDIR/public_html`` . With the default settings,
127 ``http://127.0.0.1:3456/static/foo.html`` will serve the contents of
128 ``BASEDIR/public_html/foo.html`` .
130 ``tub.port = (integer, optional)``
132 This controls which port the node uses to accept Foolscap connections
133 from other nodes. If not provided, the node will ask the kernel for any
134 available port. The port will be written to a separate file (named
135 ``client.port`` or ``introducer.port``), so that subsequent runs will
136 re-use the same port.
138 ``tub.location = (string, optional)``
140 In addition to running as a client, each Tahoe-LAFS node also runs as a
141 server, listening for connections from other Tahoe-LAFS clients. The node
142 announces its location by publishing a "FURL" (a string with some
143 connection hints) to the Introducer. The string it publishes can be found
144 in ``BASEDIR/private/storage.furl`` . The ``tub.location`` configuration
145 controls what location is published in this announcement.
147 If you don't provide ``tub.location``, the node will try to figure out a
148 useful one by itself, by using tools like "``ifconfig``" to determine the
149 set of IP addresses on which it can be reached from nodes both near and
150 far. It will also include the TCP port number on which it is listening
151 (either the one specified by ``tub.port``, or whichever port was assigned
152 by the kernel when ``tub.port`` is left unspecified).
154 You might want to override this value if your node lives behind a
155 firewall that is doing inbound port forwarding, or if you are using other
156 proxies such that the local IP address or port number is not the same one
157 that remote clients should use to connect. You might also want to control
158 this when using a Tor proxy to avoid revealing your actual IP address
159 through the Introducer announcement.
161 The value is a comma-separated string of host:port location hints, like
164 123.45.67.89:8098,tahoe.example.com:8098,127.0.0.1:8098
168 * Emulate default behavior, assuming your host has IP address
169 123.45.67.89 and the kernel-allocated port number was 8098::
172 tub.location = 123.45.67.89:8098,127.0.0.1:8098
174 * Use a DNS name so you can change the IP address more easily::
177 tub.location = tahoe.example.com:8098
179 * Run a node behind a firewall (which has an external IP address) that
180 has been configured to forward port 7912 to our internal node's port
184 tub.location = external-firewall.example.com:7912
186 * Run a node behind a Tor proxy (perhaps via ``torsocks``), in
187 client-only mode (i.e. we can make outbound connections, but other
188 nodes will not be able to connect to us). The literal
189 '``unreachable.example.org``' will not resolve, but will serve as a
190 reminder to human observers that this node cannot be reached. "Don't
191 call us.. we'll call you"::
194 tub.location = unreachable.example.org:0
196 * Run a node behind a Tor proxy, and make the server available as a Tor
197 "hidden service". (This assumes that other clients are running their
198 node with ``torsocks``, such that they are prepared to connect to a
199 ``.onion`` address.) The hidden service must first be configured in
200 Tor, by giving it a local port number and then obtaining a ``.onion``
201 name, using something in the ``torrc`` file like::
203 HiddenServiceDir /var/lib/tor/hidden_services/tahoe
204 HiddenServicePort 29212 127.0.0.1:8098
206 once Tor is restarted, the ``.onion`` hostname will be in
207 ``/var/lib/tor/hidden_services/tahoe/hostname``. Then set up your
211 tub.location = ualhejtq2p7ohfbb.onion:29212
213 Most users will not need to set ``tub.location``.
215 ``log_gatherer.furl = (FURL, optional)``
217 If provided, this contains a single FURL string that is used to contact a
218 "log gatherer", which will be granted access to the logport. This can be
219 used to gather operational logs in a single place. Note that in previous
220 releases of Tahoe-LAFS, if an old-style ``BASEDIR/log_gatherer.furl``
221 file existed it would also be used in addition to this value, allowing
222 multiple log gatherers to be used at once. As of Tahoe-LAFS v1.9.0, an
223 old-style file is ignored and a warning will be emitted if one is
224 detected. This means that as of Tahoe-LAFS v1.9.0 you can have at most
225 one log gatherer per node. See ticket `#1423`_ about lifting this
226 restriction and letting you have multiple log gatherers.
228 .. _`#1423`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1423
230 ``timeout.keepalive = (integer in seconds, optional)``
232 ``timeout.disconnect = (integer in seconds, optional)``
234 If ``timeout.keepalive`` is provided, it is treated as an integral number
235 of seconds, and sets the Foolscap "keepalive timer" to that value. For
236 each connection to another node, if nothing has been heard for a while,
237 we will attempt to provoke the other end into saying something. The
238 duration of silence that passes before sending the PING will be between
239 KT and 2*KT. This is mainly intended to keep NAT boxes from expiring idle
240 TCP sessions, but also gives TCP's long-duration keepalive/disconnect
241 timers some traffic to work with. The default value is 240 (i.e. 4
244 If timeout.disconnect is provided, this is treated as an integral number
245 of seconds, and sets the Foolscap "disconnect timer" to that value. For
246 each connection to another node, if nothing has been heard for a while,
247 we will drop the connection. The duration of silence that passes before
248 dropping the connection will be between DT-2*KT and 2*DT+2*KT (please see
249 ticket `#521`_ for more details). If we are sending a large amount of
250 data to the other end (which takes more than DT-2*KT to deliver), we
251 might incorrectly drop the connection. The default behavior (when this
252 value is not provided) is to disable the disconnect timer.
254 See ticket `#521`_ for a discussion of how to pick these timeout values.
255 Using 30 minutes means we'll disconnect after 22 to 68 minutes of
256 inactivity. Receiving data will reset this timeout, however if we have
257 more than 22min of data in the outbound queue (such as 800kB in two
258 pipelined segments of 10 shares each) and the far end has no need to
259 contact us, our ping might be delayed, so we may disconnect them by
262 .. _`#521`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/521
264 ``ssh.port = (strports string, optional)``
266 ``ssh.authorized_keys_file = (filename, optional)``
268 This enables an SSH-based interactive Python shell, which can be used to
269 inspect the internal state of the node, for debugging. To cause the node
270 to accept SSH connections on port 8022 from the same keys as the rest of
275 ssh.authorized_keys_file = ~/.ssh/authorized_keys
277 ``tempdir = (string, optional)``
279 This specifies a temporary directory for the web-API server to use, for
280 holding large files while they are being uploaded. If a web-API client
281 attempts to upload a 10GB file, this tempdir will need to have at least
282 10GB available for the upload to complete.
284 The default value is the ``tmp`` directory in the node's base directory
285 (i.e. ``BASEDIR/tmp``), but it can be placed elsewhere. This directory is
286 used for files that usually (on a Unix system) go into ``/tmp``. The
287 string will be interpreted relative to the node's base directory.
295 ``introducer.furl = (FURL string, mandatory)``
297 This FURL tells the client how to connect to the introducer. Each
298 Tahoe-LAFS grid is defined by an introducer. The introducer's FURL is
299 created by the introducer node and written into its private base
300 directory when it starts, whereupon it should be published to everyone
301 who wishes to attach a client to that grid
303 ``helper.furl = (FURL string, optional)``
305 If provided, the node will attempt to connect to and use the given helper
306 for uploads. See `<helper.rst>`_ for details.
308 ``key_generator.furl = (FURL string, optional)``
310 If provided, the node will attempt to connect to and use the given
311 key-generator service, using RSA keys from the external process rather
312 than generating its own.
314 ``stats_gatherer.furl = (FURL string, optional)``
316 If provided, the node will connect to the given stats gatherer and
317 provide it with operational statistics.
319 ``shares.needed = (int, optional) aka "k", default 3``
321 ``shares.total = (int, optional) aka "N", N >= k, default 10``
323 ``shares.happy = (int, optional) 1 <= happy <= N, default 7``
325 These three values set the default encoding parameters. Each time a new
326 file is uploaded, erasure-coding is used to break the ciphertext into
327 separate shares. There will be ``N`` (i.e. ``shares.total``) shares
328 created, and the file will be recoverable if any ``k``
329 (i.e. ``shares.needed``) shares are retrieved. The default values are
330 3-of-10 (i.e. ``shares.needed = 3``, ``shares.total = 10``). Setting
331 ``k`` to 1 is equivalent to simple replication (uploading ``N`` copies of
334 These values control the tradeoff between storage overhead and
335 reliability. To a first approximation, a 1MB file will use (1MB *
336 ``N``/``k``) of backend storage space (the actual value will be a bit
337 more, because of other forms of overhead). Up to ``N``-``k`` shares can
338 be lost before the file becomes unrecoverable. So large ``N``/``k``
339 ratios are more reliable, and small ``N``/``k`` ratios use less disk
340 space. ``N`` cannot be larger than 256, because of the 8-bit
341 erasure-coding algorithm that Tahoe-LAFS uses. ``k`` can not be greater
342 than ``N``. See `<performance.rst>`_ for more details.
344 ``shares.happy`` allows you control over how well to "spread out" the
345 shares of an immutable file. For a successful upload, shares are
346 guaranteed to be initially placed on at least ``shares.happy`` distinct
347 servers, the correct functioning of any ``k`` of which is sufficient to
348 guarantee the availability of the uploaded file. This value should not be
349 larger than the number of servers on your grid.
351 A value of ``shares.happy`` <= ``k`` is allowed, but this is not
352 guaranteed to provide any redundancy if some servers fail or lose shares.
353 It may still provide redundancy in practice if ``N`` is greater than
354 the number of connected servers, because in that case there will typically
355 be more than one share on at least some storage nodes. However, since a
356 successful upload only guarantees that at least ``shares.happy`` shares
357 have been stored, the worst case is still that there is no redundancy.
359 (Mutable files use a different share placement algorithm that does not
360 currently consider this parameter.)
362 ``mutable.format = sdmf or mdmf``
364 This value tells Tahoe-LAFS what the default mutable file format should
365 be. If ``mutable.format=sdmf``, then newly created mutable files will be
366 in the old SDMF format. This is desirable for clients that operate on
367 grids where some peers run older versions of Tahoe-LAFS, as these older
368 versions cannot read the new MDMF mutable file format. If
369 ``mutable.format`` is ``mdmf``, then newly created mutable files will use
370 the new MDMF format, which supports efficient in-place modification and
371 streaming downloads. You can overwrite this value using a special
372 mutable-type parameter in the webapi. If you do not specify a value here,
373 Tahoe-LAFS will use SDMF for all newly-created mutable files.
375 Note that this parameter applies only to files, not to directories.
376 Mutable directories, which are stored in mutable files, are not
377 controlled by this parameter and will always use SDMF. We may revisit
378 this decision in future versions of Tahoe-LAFS.
380 See `<specifications/mutable.rst>`_ for details about mutable file
383 Frontend Configuration
384 ======================
386 The Tahoe client process can run a variety of frontend file-access protocols.
387 You will use these to create and retrieve files from the virtual filesystem.
388 Configuration details for each are documented in the following
389 protocol-specific guides:
393 Tahoe runs a webserver by default on port 3456. This interface provides a
394 human-oriented "WUI", with pages to create, modify, and browse
395 directories and files, as well as a number of pages to check on the
396 status of your Tahoe node. It also provides a machine-oriented "WAPI",
397 with a REST-ful HTTP interface that can be used by other programs
398 (including the CLI tools). Please see `<frontends/webapi.rst>`_ for full
399 details, and the ``web.port`` and ``web.static`` config variables above.
400 The `<frontends/download-status.rst>`_ document also describes a few WUI
405 The main "bin/tahoe" executable includes subcommands for manipulating the
406 filesystem, uploading/downloading files, and creating/running Tahoe
407 nodes. See `<frontends/CLI.rst>`_ for details.
411 Tahoe can also run both SFTP and FTP servers, and map a username/password
412 pair to a top-level Tahoe directory. See `<frontends/FTP-and-SFTP.rst>`_
413 for instructions on configuring these services, and the ``[sftpd]`` and
414 ``[ftpd]`` sections of ``tahoe.cfg``.
418 As of Tahoe-LAFS v1.9.0, a node running on Linux can be configured to
419 automatically upload files that are created or changed in a specified
420 local directory. See `<frontends/drop-upload.rst>`_ for details.
424 Storage Server Configuration
425 ============================
429 ``enabled = (boolean, optional)``
431 If this is ``True``, the node will run a storage server, offering space
432 to other clients. If it is ``False``, the node will not run a storage
433 server, meaning that no shares will be stored on this node. Use ``False``
434 for clients who do not wish to provide storage service. The default value
437 ``readonly = (boolean, optional)``
439 If ``True``, the node will run a storage server but will not accept any
440 shares, making it effectively read-only. Use this for storage servers
441 that are being decommissioned: the ``storage/`` directory could be
442 mounted read-only, while shares are moved to other servers. Note that
443 this currently only affects immutable shares. Mutable shares (used for
444 directories) will be written and modified anyway. See ticket `#390
445 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/390>`_ for the current
446 status of this bug. The default value is ``False``.
448 ``reserved_space = (str, optional)``
450 If provided, this value defines how much disk space is reserved: the
451 storage server will not accept any share that causes the amount of free
452 disk space to drop below this value. (The free space is measured by a
453 call to ``statvfs(2)`` on Unix, or ``GetDiskFreeSpaceEx`` on Windows, and
454 is the space available to the user account under which the storage server
457 This string contains a number, with an optional case-insensitive scale
458 suffix, optionally followed by "B" or "iB". The supported scale suffixes
459 are "K", "M", "G", "T", "P" and "E", and a following "i" indicates to use
460 powers of 1024 rather than 1000. So "100MB", "100 M", "100000000B",
461 "100000000", and "100000kb" all mean the same thing. Likewise, "1MiB",
462 "1024KiB", "1024 Ki", and "1048576 B" all mean the same thing.
464 "``tahoe create-node``" generates a tahoe.cfg with
465 "``reserved_space=1G``", but you may wish to raise, lower, or remove the
466 reservation to suit your needs.
472 ``expire.override_lease_duration =``
474 ``expire.cutoff_date =``
476 ``expire.immutable =``
480 These settings control garbage collection, in which the server will
481 delete shares that no longer have an up-to-date lease on them. Please see
482 `<garbage-collection.rst>`_ for full details.
488 A "helper" is a regular client node that also offers the "upload helper"
493 ``enabled = (boolean, optional)``
495 If ``True``, the node will run a helper (see `<helper.rst>`_ for
496 details). The helper's contact FURL will be placed in
497 ``private/helper.furl``, from which it can be copied to any clients that
498 wish to use it. Clearly nodes should not both run a helper and attempt to
499 use one: do not create ``helper.furl`` and also define
500 ``[helper]enabled`` in the same node. The default is ``False``.
503 Running An Introducer
504 =====================
506 The introducer node uses a different ``.tac`` file (named
507 "``introducer.tac``"), and pays attention to the ``[node]`` section, but not
510 The Introducer node maintains some different state than regular client nodes.
512 ``BASEDIR/private/introducer.furl``
514 This is generated the first time the introducer node is started, and used
515 again on subsequent runs, to give the introduction service a persistent
516 long-term identity. This file should be published and copied into new
517 client nodes before they are started for the first time.
520 Other Files in BASEDIR
521 ======================
523 Some configuration is not kept in ``tahoe.cfg``, for the following reasons:
525 * it is generated by the node at startup, e.g. encryption keys. The node
526 never writes to ``tahoe.cfg``.
527 * it is generated by user action, e.g. the "``tahoe create-alias``" command.
529 In addition, non-configuration persistent state is kept in the node's base
530 directory, next to the configuration knobs.
532 This section describes these other files.
536 This contains an SSL private-key certificate. The node generates this the
537 first time it is started, and re-uses it on subsequent runs. This
538 certificate allows the node to have a cryptographically-strong identifier
539 (the Foolscap "TubID"), and to establish secure connections to other nodes.
543 Nodes that host StorageServers will create this directory to hold shares of
544 files on behalf of other clients. There will be a directory underneath it
545 for each StorageIndex for which this node is holding shares. There is also
546 an "incoming" directory where partially-completed shares are held while
547 they are being received.
551 This file defines the client, by constructing the actual Client instance
552 each time the node is started. It is used by the "``twistd``" daemonization
553 program (in the ``-y`` mode), which is run internally by the "``tahoe
554 start``" command. This file is created by the "``tahoe create-node``" or
555 "``tahoe create-client``" commands.
557 ``tahoe-introducer.tac``
559 This file is used to construct an introducer, and is created by the
560 "``tahoe create-introducer``" command.
562 ``tahoe-key-generator.tac``
564 This file is used to construct a key generator, and is created by the
565 "``tahoe create-key-gernerator``" command.
567 ``tahoe-stats-gatherer.tac``
569 This file is used to construct a statistics gatherer, and is created by the
570 "``tahoe create-stats-gatherer``" command.
572 ``private/control.furl``
574 This file contains a FURL that provides access to a control port on the
575 client node, from which files can be uploaded and downloaded. This file is
576 created with permissions that prevent anyone else from reading it (on
577 operating systems that support such a concept), to insure that only the
578 owner of the client node can use this feature. This port is intended for
579 debugging and testing use.
581 ``private/logport.furl``
583 This file contains a FURL that provides access to a 'log port' on the
584 client node, from which operational logs can be retrieved. Do not grant
585 logport access to strangers, because occasionally secret information may be
588 ``private/helper.furl``
590 If the node is running a helper (for use by other clients), its contact
591 FURL will be placed here. See `<helper.rst>`_ for more details.
593 ``private/root_dir.cap`` (optional)
595 The command-line tools will read a directory cap out of this file and use
596 it, if you don't specify a '--dir-cap' option or if you specify
599 ``private/convergence`` (automatically generated)
601 An added secret for encrypting immutable files. Everyone who has this same
602 string in their ``private/convergence`` file encrypts their immutable files
603 in the same way when uploading them. This causes identical files to
604 "converge" -- to share the same storage space since they have identical
605 ciphertext -- which conserves space and optimizes upload time, but it also
606 exposes file contents to the possibility of a brute-force attack by people
607 who know that string. In this attack, if the attacker can guess most of the
608 contents of a file, then they can use brute-force to learn the remaining
611 So the set of people who know your ``private/convergence`` string is the
612 set of people who converge their storage space with you when you and they
613 upload identical immutable files, and it is also the set of people who
614 could mount such an attack.
616 The content of the ``private/convergence`` file is a base-32 encoded
617 string. If the file doesn't exist, then when the Tahoe-LAFS client starts
618 up it will generate a random 256-bit string and write the base-32 encoding
619 of this string into the file. If you want to converge your immutable files
620 with as many people as possible, put the empty string (so that
621 ``private/convergence`` is a zero-length file).
629 Each Tahoe-LAFS node creates a directory to hold the log messages produced
630 as the node runs. These logfiles are created and rotated by the
631 "``twistd``" daemonization program, so ``logs/twistd.log`` will contain the
632 most recent messages, ``logs/twistd.log.1`` will contain the previous ones,
633 ``logs/twistd.log.2`` will be older still, and so on. ``twistd`` rotates
634 logfiles after they grow beyond 1MB in size. If the space consumed by
635 logfiles becomes troublesome, they should be pruned: a cron job to delete
636 all files that were created more than a month ago in this ``logs/``
637 directory should be sufficient.
641 this is written by all nodes after startup, and contains a base32-encoded
642 (i.e. human-readable) NodeID that identifies this specific node. This
643 NodeID is the same string that gets displayed on the web page (in the
644 "which peers am I connected to" list), and the shortened form (the first
645 few characters) is recorded in various log messages.
649 Gateway nodes may find it necessary to prohibit access to certain
650 files. The web-API has a facility to block access to filecaps by their
651 storage index, returning a 403 "Forbidden" error instead of the original
652 file. For more details, see the "Access Blacklist" section of
653 `<frontends/webapi.rst>`_.
659 The following is a sample ``tahoe.cfg`` file, containing values for some of
660 the keys described in the previous section. Note that this is not a
661 recommended configuration (most of these are not the default values), merely
667 nickname = Bob's Tahoe-LAFS Node
669 tub.location = 123.45.67.89:8098,44.55.66.77:8098
671 log_gatherer.furl = pb://soklj4y7eok5c3xkmjeqpw@192.168.69.247:44801/eqpwqtzm
672 timeout.keepalive = 240
673 timeout.disconnect = 1800
675 ssh.authorized_keys_file = ~/.ssh/authorized_keys
678 introducer.furl = pb://ok45ssoklj4y7eok5c3xkmj@tahoe.example:44801/ii3uumo
679 helper.furl = pb://ggti5ssoklj4y7eok5c3xkmj@helper.tahoe.example:7054/kk8lhr
684 reserved_space = 10000000000
690 Old Configuration Files
691 =======================
693 Tahoe-LAFS releases before v1.3.0 had no ``tahoe.cfg`` file, and used
694 distinct files for each item. This is no longer supported and if you have
695 configuration in the old format you must manually convert it to the new
696 format for Tahoe-LAFS to detect it. See `<historical/configuration.rst>`_.