Changes between Version 81 and Version 82 of FAQ


Ignore:
Timestamp:
2012-10-03T19:56:40Z (12 years ago)
Author:
zooko
Comment:

make links to source all go to /git/, not to /trunk/, to avoid troublesome darcs

Legend:

Unmodified
Added
Removed
Modified

  • FAQ

    v81 v82  
    55'''[=#Q1_why_tahoe_lafs Q1:] What is special about Tahoe-LAFS? Why should anyone care about it instead of [wiki:RelatedProjects#OtherProjects other distributed storage systems]?'''
    66
    7 A1: Tahoe-LAFS is the first Free !Software/Open Source storage technology to offer ''provider-independent security''.  ''Provider-independent security'' means that the integrity and confidentiality of your files is guaranteed by mathematics computed on the client side, and is independent of the servers, which may be owned and operated by someone else.  To learn more, read [source:docs/about.rst our one-page explanation].
     7A1: Tahoe-LAFS is the first Free !Software/Open Source storage technology to offer ''provider-independent security''.  ''Provider-independent security'' means that the integrity and confidentiality of your files is guaranteed by mathematics computed on the client side, and is independent of the servers, which may be owned and operated by someone else.  To learn more, read [source:git/docs/about.rst our one-page explanation].
    88
    99A2: Tahoe-LAFS provides reliable, fault-tolerant storage. Even if you do not need its security properties, you might want to use Tahoe-LAFS for extremely reliable storage. (Tahoe-LAFS's security features do a good job of staying out of your way when you don't need them.)
    … …  
    2929'''[=#Q4_where_are_the_docs Q4:] Where should I look for current documentation about the Tahoe-LAFS protocols?'''
    3030
    31 A: [source:docs/architecture.rst https://tahoe-lafs.org/trac/tahoe-lafs/browser/docs/architecture.rst]
     31A: [source:git/docs/architecture.rst https://tahoe-lafs.org/trac/tahoe-lafs/browser/docs/architecture.rst]
    3232
    3333'''[=#Q5_embedded_devices Q5:] Does Tahoe-LAFS work on embedded devices such as a [http://www.pogoplug.com PogoPlug] or an [http://openwrt.org OpenWRT] router?'''
    … …  
    3939'''[=#Q6_windows Q6:] Does Tahoe-LAFS work on Windows?'''
    4040
    41 A: Yes.  Follow [source:docs/quickstart.rst the standard quickstart instructions] to get Tahoe-LAFS running on Windows. (There was also an "Allmydata Windows client", but that is not actively maintained at the moment, and relied on some components that are not open-source.)
     41A: Yes.  Follow [source:git/docs/quickstart.rst the standard quickstart instructions] to get Tahoe-LAFS running on Windows. (There was also an "Allmydata Windows client", but that is not actively maintained at the moment, and relied on some components that are not open-source.)
    4242
    4343'''[=#Q7_mac_os_x Q7:] Does Tahoe-LAFS work on Mac OS X?'''
    4444
    45 A: Yes.  Follow [source:docs/quickstart.rst the standard quickstart instructions] on Mac OS X and it will result in a working command-line tool on Mac OS X just as it does on other Unixes.
     45A: Yes.  Follow [source:git/docs/quickstart.rst the standard quickstart instructions] on Mac OS X and it will result in a working command-line tool on Mac OS X just as it does on other Unixes.
    4646
    4747'''[=#Q8_storage_in_multiple_dirs Q8:] Can there be more than one storage directory on a storage node? So if a storage server contains 3 drives without RAID, can it use all 3 for storage?'''
    … …  
    126126A: Tahoe-LAFS is designed to be unobtrusive. First of all, it doesn't start at all except when you tell it to—you start it with {{{tahoe start}}} and stop it with {{{tahoe stop}}}. Secondly, the software doesn't act as a server unless you configure it to do so—it isn't like peer-to-peer software which automatically acts as a server as well as a client. Thirdly, the client doesn't do anything except in response to the user starting an upload or a download—it doesn't do anything automatically or in the background (this might change in future, to support background repair for example, but probably only if you explicitly enable it). Fourthly, with two minor exceptions described below, the server doesn't do anything either, except in response to clients doing uploads or downloads. Finally, even when the server is actively serving clients it isn't too intensive of a process. It uses between 40 and 56 MB of RAM on a 64-bit Linux server. We used to run eight of them on a single-core 2 GHz Opteron and had plenty of CPU to spare, so it isn't too CPU intensive.
    127127
    128 The two minor exceptions are that the server periodically inspects all of the ciphertext that it is storing on behalf of clients. It is configured to do this "in the background", by doing it only for a second at a time and waiting for a few seconds in between each step. The intent is that this will not noticably impact other users of the same server. For all the details about when these background processes run and what they do, read the documentation in [source:trunk/src/allmydata/storage/crawler.py?annotate=blame&rev=4164 storage/crawler.py] and [source:trunk/src/allmydata/storage/expirer.py?annotate=blame&rev=4329 storage/expirer.py].
     128The two minor exceptions are that the server periodically inspects all of the ciphertext that it is storing on behalf of clients. It is configured to do this "in the background", by doing it only for a second at a time and waiting for a few seconds in between each step. The intent is that this will not noticably impact other users of the same server. For all the details about when these background processes run and what they do, read the documentation in XXX [source:git/src/allmydata/storage/crawler.py?annotate=blame&rev=3cb99364e6a83d0064d2838a0c470278903e19ac storage/crawler.py] and [source:git/src/allmydata/storage/expirer.py?annotate=blame&rev=e76092e16c64019857441e9020d6d8ba2bdaa0bc storage/expirer.py].
    129129
    130130
    … …  
    149149
    150150A:
    151 Literal caps (or LIT caps) are simply the base32 encoding of the file data, and are used for very small files. The threshold is 55 bytes (source: [source:trunk/src/allmydata/immutable/upload.py?rev=5232#L1410 immutable/upload.py]), which is
     151Literal caps (or LIT caps) are simply the base32 encoding of the file data, and are used for very small files. The threshold is 55 bytes (source: XXX [source:git/src/allmydata/immutable/upload.py?annotate=blame&rev=196bd583b6c4959c60d3f73cdcefc9edda6a38ae#L1504 immutable/upload.py]), which is
    152152the break-even point at which the LIT filecap is the same length as a typical CHK filecap. They are sufficient (you don't even need network access to turn the LIT filecap into the data), and necessary (if you don't know the filecap for my data, you can't figure out the data). See this mailing list thread:
    153153* [//pipermail/tahoe-dev/2010-April/004235.html Storing a small file leads to a weird read capability] (especially [//pipermail/tahoe-dev/2010-April/004237.html this message by Brian Warner])
    … …  
    158158
    159159A:
    160 Yes. Tahoe-LAFS comes with an [source:docs/frontends/FTP-and-SFTP.rst SFTP server]. If you point [http://fuse.sourceforge.net/sshfs.html sshfs] at the SFTP server then you have access to Tahoe-LAFS through FUSE. Alternately, [wiki:pyFilesystem pyfilesystem] interfaces directly with Tahoe-LAFS through the latter's [source:docs/frontends/webapi.rst WAPI] and provides both FUSE and Microsoft Windows filesystem access. See #1353 for discussion of possible improvements to FUSE integration. See [http://lists.alioth.debian.org/pipermail/freedombox-discuss/2011-November/003162.html Zooko's post to freedombox-discuss] and [https://plus.google.com/108313527900507320366/posts/ZrgdgLhV3NG Zooko's post to Google+] for Zooko's ramblings about the advisability of using FUSE for distributed filesystems in general and Tahoe-LAFS in particular.
     160Yes. Tahoe-LAFS comes with an [source:git/docs/frontends/FTP-and-SFTP.rst SFTP server]. If you point [http://fuse.sourceforge.net/sshfs.html sshfs] at the SFTP server then you have access to Tahoe-LAFS through FUSE. Alternately, [wiki:pyFilesystem pyfilesystem] interfaces directly with Tahoe-LAFS through the latter's [source:git/docs/frontends/webapi.rst WAPI] and provides both FUSE and Microsoft Windows filesystem access. See #1353 for discussion of possible improvements to FUSE integration. See [http://lists.alioth.debian.org/pipermail/freedombox-discuss/2011-November/003162.html Zooko's post to freedombox-discuss] and [https://plus.google.com/108313527900507320366/posts/ZrgdgLhV3NG Zooko's post to Google+] for Zooko's ramblings about the advisability of using FUSE for distributed filesystems in general and Tahoe-LAFS in particular.
    161161
    162162'''[=#Q24_smallgrid Q24:] How I should setup k,h,N on my small private grid?''