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layout: default
navsection: admin
title: Recovering deleted collections
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Copyright (C) The Arvados Authors. All rights reserved.

SPDX-License-Identifier: CC-BY-SA-3.0
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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 recover-collection@ 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 @recover-collection@ program saves the recovered data a new collection belonging to the system user, and prints the new collection's UUID on stdout.

<pre>
# arvados-server recover-collection 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 recover-collection -help@.