16427: Add "undeleting collections" doc page in admin section.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@tomclegg.ca>

diff --git a/doc/_config.yml b/doc/_config.yml
index 48fe1b53d49149139cf36e0b602e0f0fe4d2ab3e..9f016fcc8c01a0aa56283867d44e6a13e2efc1e4 100644 (file)
--- a/doc/_config.yml
+++ b/doc/_config.yml
@@ -174,6 +174,7 @@ navbar:
       - admin/logs-table-management.html.textile.liquid
       - admin/workbench2-vocabulary.html.textile.liquid
       - admin/storage-classes.html.textile.liquid
+      - admin/undeleting-collections.html.textile.liquid
     - Cloud:
       - admin/spot-instances.html.textile.liquid
       - admin/cloudtest.html.textile.liquid

diff --git a/doc/admin/undeleting-collections.html.textile.liquid b/doc/admin/undeleting-collections.html.textile.liquid
new file mode 100644 (file)
index 0000000..461671b
--- /dev/null
+++ b/doc/admin/undeleting-collections.html.textile.liquid
@@ -0,0 +1,37 @@
+---
+layout: default
+navsection: admin
+title: Undeleting collections
+...
+
+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
+
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
+
+In some cases, it is possible to recover files that have been lost by modifying or deleting a collection.
+
+Possibility of recovery depends on many factors, including:
+* Whether the collection manifest is still available, e.g., in an audit log entry
+* Whether the data blocks are also referenced by other collections
+* Whether the data blocks have been unreferenced long enough to be marked for deletion/trash by keep-balance
+* Blob signature TTL, trash lifetime, trash check interval, and other config settings
+
+To attempt recovery of a previous version of a deleted/modified collection, use the @arvados-server undelete@ command. It should be run on one of your server nodes where the @arvados-server@ package is installed and the @/etc/arvados/config.yml@ file is up to date.
+
+Specify the collection you want to recover by passing either the UUID of an audit log entry, or a file containing the manifest.
+
+If recovery is successful, the undelete program saves the recovered data a new collection belonging to the system user, and print the new collection's UUID on stdout.
+
+<pre>
+# arvados-server undelete 9tee4-57u5n-nb5awmk1pahac2t
+INFO[2020-06-05T19:52:29.557761245Z] loaded log entry                              logged_event_time="2020-06-05 16:48:01.438791 +0000 UTC" logged_event_type=update old_collection_uuid=9tee4-4zz18-1ex26g95epmgw5w src=9tee4-57u5n-nb5awmk1pahac2t
+INFO[2020-06-05T19:52:29.642145127Z] recovery succeeded                            UUID=9tee4-4zz18-5trfp4k4xxg97f1 src=9tee4-57u5n-nb5awmk1pahac2t
+9tee4-4zz18-5trfp4k4xxg97f1
+INFO[2020-06-05T19:52:29.644699436Z] exiting
+</pre>
+
+In this example, the original data has been restored and saved in a new collection with UUID @9tee4-4zz18-5trfp4k4xxg97f1@.
+
+For more options, run @arvados-server undelete -help@.