-h1. Storing and Retrieving data using Arvados Keep
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-This tutorial introduces you to the Arvados file storage system.
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-*This tutorial assumes that you are "logged into an Arvados VM instance":{{site.basedoc}}/user/getting_started/ssh-access.html#login, and have a "working environment.":{{site.basedoc}}/user/getting_started/check-environment.html*
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-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:
-* Files can be stored and replicated across a cluster of servers without requiring a central name server.
-* Systematic validation of data integrity by both server and client because the checksum is built into the identifier.
-* Minimizes data duplication (two files with the same contents will result in the same identifier, and will not be stored twice.)
-* Avoids data race conditions (an identifier always points to the same data.)
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-h1. Putting Data into Keep
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-We will start with downloading a freely available VCF file from the "Personal Genome Project (PGP)":http://www.personalgenomes.org subject "hu599905":https://my.personalgenomes.org/profile/hu599905 to a staging directory on the VM, and then add it to Keep.