X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/77f1129ec53edffb5ed5a859106675cf262977e8..5ff4dac7a9ee28eb35a796b80421a6d3d1e5ecd0:/doc/user/topics/keep.html.textile.liquid
diff --git a/doc/user/topics/keep.html.textile.liquid b/doc/user/topics/keep.html.textile.liquid
index f96642937e..68b6a87d09 100644
--- a/doc/user/topics/keep.html.textile.liquid
+++ b/doc/user/topics/keep.html.textile.liquid
@@ -3,8 +3,13 @@ layout: default
navsection: userguide
title: "How Keep works"
...
+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
-The Arvados distributed file system is called *Keep*. Keep is a content-addressable file system. This means that files are managed using special unique identifiers derived from the _contents_ of the file, rather than human-assigned file names (specifically, the MD5 hash). This has a number of advantages:
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
+
+The Arvados distributed file system is called *Keep*. Keep is a content-addressable file system. This means that files are managed using special unique identifiers derived from the _contents_ of the file (specifically, the MD5 hash), rather than human-assigned file names. This has a number of advantages:
* Files can be stored and replicated across a cluster of servers without requiring a central name server.
* Both the server and client systematically validate data integrity because the checksum is built into the identifier.
* Data duplication is minimizedâtwo files with the same contents will have in the same identifier, and will not be stored twice.
@@ -14,20 +19,20 @@ In Keep, information is stored in *data blocks*. Data blocks are normally betwe
In order to reassemble the file, Keep stores a *collection* data block which lists in sequence the data blocks that make up the original file. A collection data block may store the information for multiple files, including a directory structure.
-In this example we will use @c1bad4b39ca5a924e481008009d94e32+210@ which we added to Keep in "the first Keep tutorial":{{ site.baseurl }}/user/tutorials/tutorial-keep.html. First let us examine the contents of this collection using @arv keep get@:
+In this example we will use @c1bad4b39ca5a924e481008009d94e32+210@, which we added to Keep in "how to upload data":{{ site.baseurl }}/user/tutorials/tutorial-keep.html. First let us examine the contents of this collection using @arv-get@:
~$ arv keep get c1bad4b39ca5a924e481008009d94e32+210
+
~$ arv-get c1bad4b39ca5a924e481008009d94e32+210
. 204e43b8a1185621ca55a94839582e6f+67108864 b9677abbac956bd3e86b1deb28dfac03+67108864 fc15aff2a762b13f521baf042140acec+67108864 323d2a3ce20370c4ca1d3462a344f8fd+25885655 0:227212247:var-GS000016015-ASM.tsv.bz2
~$ cd /scratch/you
-/scratch/you$ arv keep get 204e43b8a1185621ca55a94839582e6f+67108864 > block1
+/scratch/you$ arv-get 204e43b8a1185621ca55a94839582e6f+67108864 > block1
{% include 'notebox_begin' %}
@@ -35,7 +40,7 @@ When you run this command, you may get this API warning:
notextile. WARNING:root:API lookup failed for collection 204e43b8a1185621ca55a94839582e6f+67108864 (<class 'apiclient.errors.HttpError'>: <HttpError 404 when requesting https://qr1hi.arvadosapi.com/arvados/v1/collections/204e43b8a1185621ca55a94839582e6f%2B67108864?alt=json returned "Not Found">)
-This happens because @arv keep get@ tries to find a collection with this identifier. When that fails, it emits this warning, then looks for a datablock instead, which succeeds.
+This happens because @arv-get@ tries to find a collection with this identifier. When that fails, it emits this warning, then looks for a datablock instead, which succeeds.
{% include 'notebox_end' %}