s/node/client; mention restart is needed

This commit is contained in:
Zooko O'Whielacronx 2013-04-09 00:48:23 -06:00 committed by Brian Warner
parent 07f7d50afa
commit 643eb4f372
1 changed files with 17 additions and 14 deletions

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@ -5,16 +5,16 @@ What Is It?
The identifer of a file (also called the "capability" to a file) is derived The identifer of a file (also called the "capability" to a file) is derived
from two pieces of information when the file is uploaded: the content of the from two pieces of information when the file is uploaded: the content of the
file and the upload node's "convergence secret". By default, the convergence file and the upload client's "convergence secret". By default, the
secret is randomly generated by the node when it first starts up, then stored convergence secret is randomly generated by the client when it first starts
in the node's base directory (<Tahoe's node dir>/private/convergence) and up, then stored in the client's base directory (<Tahoe's node
re-used after that. So the same file content uploaded from the same node will dir>/private/convergence) and re-used after that. So the same file content
always have the same cap. Uploading the file from a different node with a uploaded from the same client will always have the same cap. Uploading the
different convergence secret would result in a different cap—and in a second file from a different client with a different convergence secret would result
copy of the file's contents stored on the grid. If you want files you upload in a different cap—and in a second copy of the file's contents stored on the
to converge (also known as "deduplicate") with files uploaded by someone grid. If you want files you upload to converge (also known as "deduplicate")
else, just make sure you're using the same convergence secret when you upload with files uploaded by someone else, just make sure you're using the same
files as they convergence secret when you upload files as they
The advantages of deduplication should be clear, but keep in mind that the The advantages of deduplication should be clear, but keep in mind that the
convergence secret was created to protect confidentiality. There are two convergence secret was created to protect confidentiality. There are two
@ -54,8 +54,8 @@ All your old file capabilities will still work, but the new data that you
upload will not be deduplicated with the old data. If you upload all of the upload will not be deduplicated with the old data. If you upload all of the
same things to the grid, you will end up using twice the space until garbage same things to the grid, you will end up using twice the space until garbage
collection kicks in (if it's enabled). Changing the convergence secret that a collection kicks in (if it's enabled). Changing the convergence secret that a
node uses for uploads can be though of as moving the node to a new storage client uses for uploads can be though of as moving the client to a
"deduplication domain". new "deduplication domain".
How To Use It How To Use It
------------- -------------
@ -69,7 +69,10 @@ scp installed, run:
*scp ~/.tahoe/private/convergence *scp ~/.tahoe/private/convergence
my_other_account@B:.tahoe/private/convergence* my_other_account@B:.tahoe/private/convergence*
If you have two different nodes on a single computer, say one for each disk, If you have two different clients on a single computer, say one for each
you would do: disk, you would do:
*cp /tahoe1/private/convergence /tahoe2/private/convergence* *cp /tahoe1/private/convergence /tahoe2/private/convergence*
After you change the convergence secret file, you must restart the client
before it will stop using the old one and read the new one from the file.