faq: updates, fixes

docs/faq.rst

@@ -16,16 +16,16 @@ Can I backup VM disk images?
     Also, we have optional simple sparse file support for extract.
 
 Can I backup from multiple servers into a single repository?
-    Yes, but in order for the deduplication used by Borg to work, it
+    Yes, but in order for the deduplication used by |project_name| to work, it
     needs to keep a local cache containing checksums of all file
     chunks already stored in the repository. This cache is stored in
-    ``~/.cache/borg/``.  If Borg detects that a repository has been
+    ``~/.cache/borg/``.  If |project_name| detects that a repository has been
     modified since the local cache was updated it will need to rebuild
     the cache. This rebuild can be quite time consuming.
 
     So, yes it's possible. But it will be most efficient if a single
     repository is only modified from one place. Also keep in mind that
-    Borg will keep an exclusive lock on the repository while creating
+    |project_name| will keep an exclusive lock on the repository while creating
     or deleting archives, which may make *simultaneous* backups fail.
 
 Which file types, attributes, etc. are preserved?
@@ -62,8 +62,18 @@ How can I specify the encryption passphrase programmatically?
     key file based encryption with a blank passphrase. See
     :ref:`encrypted_repos` for more details.
 
-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?
-    Yes, everything is encrypted before leaving the local machine.
+When backing up to remote encrypted repos, is encryption done locally?
+    Yes, file and directory metadata and data is locally encrypted, before
+    leaving the local machine. We do not mean the transport layer encryption
+    by that, but the data/metadata itself. Transport layer encryption (e.g.
+    when ssh is used as a transport) applies additionally.
+
+When backing up to remote servers, do I have to trust the remote server?
+    Yes and No.
+    No, as far as data confidentiality is concerned - all your files/dirs data
+    and metadata are stored in their encrypted form into the repository.
+    Yes, as an attacker with access to the remote server could delete (or
+    otherwise make unavailable) all your backups.
 
 If a backup stops mid-way, does the already-backed-up data stay there? I.e. does |project_name| resume backups?
     Yes, during a backup a special checkpoint archive named ``<archive-name>.checkpoint`` is saved every 5 minutes
@@ -75,11 +85,17 @@ If it crashes with a UnicodeError, what can I do?
 
         export LANG=en_US.UTF-8  # or similar, important is correct charset
 
+If I want to run |project_name| on a ARM CPU older than ARM v6?
+    You need to enable the alignment trap handler to fixup misaligned accesses:
+    
+        echo "2" > /proc/cpu/alignment
+
 Why was Borg forked from Attic?
-    Borg was created in may 2015 in response to the difficulty of
-    getting new merge requests and larger changes incorporated into
-    attic. more details can be found in the fairly long discussion
-    in attic issue queue (found in `ticket 217
+    Borg was created in May 2015 in response to the difficulty of
+    getting new code or larger changes incorporated into Attic and
+    establishing a bigger developer community / more open development.
+
+    More details can be found in `ticket 217
     <https://github.com/jborg/attic/issues/217>`_) that led to the fork.
 
     Borg intends to be:
@@ -93,7 +109,7 @@ Why was Borg forked from Attic?
       * give feedback on PRs that can't be accepted "as is"
       * discuss openly, don't work in the dark
     * changing:
+      * Borg is not compatible with Attic
       * do not break compatibility accidentally, without a good reason
-        or without warning
-      * Borg is not backwards-compatible with attic
-      * major versions may not be compatible with older releases
+        or without warning. allow compatibility breaking for other cases.
+      * if major version number changes, it may have incompatible changes