2013-06-29 21:56:44 +00:00
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.. _faq:
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.. include:: global.rst.inc
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Frequently asked questions
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==========================
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Which platforms are supported?
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2013-07-31 18:51:01 +00:00
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Currently Linux, FreeBSD and MacOS X are supported.
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2013-07-30 19:51:21 +00:00
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2013-06-29 21:56:44 +00:00
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Can I backup VM disk images?
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2013-07-31 18:51:01 +00:00
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Yes, the :ref:`deduplication <deduplication_def>` technique used by |project_name|
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makes sure only the modified parts of the file are stored.
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2013-07-30 19:51:21 +00:00
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2014-12-16 16:16:30 +00:00
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Can I backup from multiple servers into a single repository?
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Yes, but in order for the deduplication used by Attic to work, it
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needs to keep a local cache containing checksums of all file
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chunks already stored in the repository. This cache is stored in
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``~/.cache/attic/``. If Attic detects that a repository has been
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modified since the local cache was updated it will need to rebuild
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the cache. This rebuild can be quite time consuming.
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So, yes it's possible. But it will be most efficient if a single
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repository is only modified from one place.
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2013-06-29 21:56:44 +00:00
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Which file attributes are preserved?
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2013-07-31 18:51:01 +00:00
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The following attributes are preserved:
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2013-06-29 21:56:44 +00:00
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2013-07-31 18:51:01 +00:00
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* Name
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* Contents
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* Time of last modification (nanosecond precision with Python >= 3.3)
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* User ID of owner
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* Group ID of owner
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* Unix Permission
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* Extended attributes (xattrs)
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2014-05-03 21:27:01 +00:00
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* Access Control Lists (ACL_) on Linux, OS X and FreeBSD
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* BSD flags on OS X and FreeBSD
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2013-07-30 19:51:21 +00:00
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How can I specify the encryption passphrase programmatically?
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2013-07-31 18:51:01 +00:00
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The encryption passphrase can be specified programmatically using the
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`ATTIC_PASSPHRASE` environment variable. This is convenient when setting up
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automated encrypted backups. Another option is to use
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key file based encryption with a blank passphrase. See
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:ref:`encrypted_repos` for more details.
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2014-04-05 19:08:11 +00:00
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When backing up to remote servers, is data encrypted before leaving the local machine, or do I have to trust that the remote server isn't malicious?
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Yes, everything is encrypted before leaving the local machine.
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If a backup stops mid-way, does the already-backed-up data stay there? I.e. does Attic resume backups?
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Yes, during a backup a special checkpoint archive named ``<archive-name>.snapshot`` is saved every 5 minutes
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containing all the data backed-up until that point. This means that at most 5 minutes worth of data needs to be
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retransmitted if a backup needs to be restarted.
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