X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=doc%2Fchunked.texi;h=d0f111aa96366969e872cae60bdf6957e2b9c41c;hb=bb7fe5e770586be9f44a8a7f3321a3139d5345bb;hp=5bdbc22dab5abe9e3386146a012c46c5daf33608;hpb=71fef454f38565b87e8697f86b071a57b3a3c379;p=nncp.git

diff --git a/doc/chunked.texi b/doc/chunked.texi
index 5bdbc22..d0f111a 100644
--- a/doc/chunked.texi
+++ b/doc/chunked.texi
@@ -1,7 +1,8 @@
 @node Chunked
+@cindex chunked
 @unnumbered Chunked files
 
-There is ability to transfer huge files with splitting them into smaller
+There is ability to transfer huge files with dividing them into smaller
 chunks. Each chunk is treated like a separate file, producing separate
 outbound packet unrelated with other ones.
 
@@ -10,16 +11,18 @@ than huge file's size. You can transfer those chunks on different
 storage devices, and/or at different time, reassembling the whole packet
 on the destination node.
 
-Splitting is done with @ref{nncp-file, nncp-file -chunk} command and
-reassembling with @ref{nncp-reass} command.
+Splitting is done with @command{@ref{nncp-file} -chunked} command and
+reassembling with @command{@ref{nncp-reass}} command.
 
+@vindex .nncp.meta
+@vindex .nncp.chunk
 Chunked @file{FILE} produces @file{FILE.nncp.meta},
-@file{FILE.nncp.chunk0}, @file{FILE.nncp.chunk1}, ... files. All
+@file{FILE.nncp.chunk0}, @file{FILE.nncp.chunk1}, @dots{} files. All
 @file{.nncp.chunkXXX} can be concatenated together to produce original
 @file{FILE}.
 
 @file{.nncp.meta} contains information about file/chunk
-size and their hash checksums. It is
+size and their hash checksums. This is
 @url{https://tools.ietf.org/html/rfc4506, XDR}-encoded structure:
 
 @verbatim
@@ -29,17 +32,28 @@ size and their hash checksums. It is
 @end verbatim
 
 @multitable @columnfractions 0.2 0.3 0.5
-@headitem  @tab XDR type @tab Value
+@headitem @tab XDR type @tab Value
 @item Magic number @tab
     8-byte, fixed length opaque data @tab
-    @verb{|N N C P M 0x00 0x00 0x01|}
+    @verb{|N N C P M 0x00 0x00 0x02|}
 @item File size @tab
     unsigned hyper integer @tab
     Whole reassembled file's size
 @item Chunk size @tab
     unsigned hyper integer @tab
-    Size of each chunks (except for the last one, that could be smaller).
+    Size of each chunk (except for the last one, that could be smaller)
 @item Checksums @tab
     variable length array of 32 byte fixed length opaque data @tab
-    BLAKE2b-256 checksum of each chunk
+    @ref{MTH} checksum of each chunk
 @end multitable
+
+@cindex ZFS recordsize
+@anchor{ChunkedZFS}
+It is strongly advisable to reassemble incoming chunked files on
+@url{https://en.wikipedia.org/wiki/ZFS, ZFS} dataset with deduplication
+feature enabled. It could be more CPU and memory hungry, but will save
+your disk's IO and free space from pollution (although temporary). But
+pay attention that you chunks must be either equal to, or divisible by
+dataset's @option{recordsize} value for deduplication workability.
+Default ZFS's @option{recordsize} is 128 KiBs, so it is advisable to
+chunk your files on 128, 256, 384, 512, etc KiB blocks.