Amazon Glacier special remote; 100% working

Assistant/WebApp/Configurators/S3.hs

@@ -17,6 +17,7 @@ import Assistant.WebApp.Types
 import Assistant.WebApp.SideBar
 import Utility.Yesod
 import qualified Remote.S3 as S3
+import qualified Remote.Helper.AWS as AWS
 import Logs.Remote
 import qualified Remote
 import Types.Remote (RemoteConfig)
@@ -113,7 +114,7 @@ getEnableS3R uuid = s3Configurator $ do
 makeS3Remote :: S3Creds -> String -> (Remote -> Handler ()) -> RemoteConfig -> Handler ()
 makeS3Remote (S3Creds ak sk) name setup config = do
 	remotename <- runAnnex name $ fromRepo $ uniqueRemoteName name 0
-	liftIO $ S3.setCredsEnv (T.unpack ak, T.unpack sk)
+	liftIO $ AWS.setCredsEnv (T.unpack ak, T.unpack sk)
 	r <- liftAssistant $ liftAnnex $ addRemote $ do
 		makeSpecialRemote name S3.remote config
 		return remotename

Creds.hs

@@ -34,7 +34,7 @@ data CredPairStorage = CredPairStorage
 {- Stores creds in a remote's configuration, if the remote allows
  - that. Otherwise, caches them locally. -}
 setRemoteCredPair :: RemoteConfig -> CredPairStorage -> Annex RemoteConfig
-setRemoteCredPair c storage = go =<< getRemoteCredPair c storage
+setRemoteCredPair c storage = go =<< getRemoteCredPair' c storage
   where
 	go (Just creds)
 		| embedCreds c = case credPairRemoteKey storage of
@@ -58,8 +58,20 @@ setRemoteCredPair c storage = go =<< getRemoteCredPair c storage
 {- Gets a remote's credpair, from the environment if set, otherwise
  - from the cache in gitAnnexCredsDir, or failing that, from the
  - value in RemoteConfig. -}
-getRemoteCredPair :: RemoteConfig -> CredPairStorage -> Annex (Maybe CredPair)
+getRemoteCredPair :: String -> RemoteConfig -> CredPairStorage -> Annex (Maybe CredPair)
-getRemoteCredPair c storage = maybe fromcache (return . Just) =<< fromenv
+getRemoteCredPair this c storage = maybe missing (return . Just) =<< getRemoteCredPair' c storage
+  where
+	(loginvar, passwordvar) = credPairEnvironment storage
+	missing = do
+		warning $ unwords
+			[ "Set both", loginvar
+			, "and", passwordvar
+			, "to use", this
+			]
+		return Nothing
+
+getRemoteCredPair' :: RemoteConfig -> CredPairStorage -> Annex (Maybe CredPair)
+getRemoteCredPair' c storage = maybe fromcache (return . Just) =<< fromenv
   where
 	fromenv = liftIO $ getEnvCredPair storage
 	fromcache = maybe fromconfig (return . Just) =<< readCacheCredPair storage
@@ -91,6 +103,8 @@ getEnvCredPair storage = liftM2 (,)
 	(uenv, penv) = credPairEnvironment storage
 	get = catchMaybeIO . getEnv
 
+
+
 {- Stores a CredPair in the environment. -}
 setEnvCredPair :: CredPair -> CredPairStorage -> IO ()
 setEnvCredPair (l, p) storage = do

GitAnnex.hs

@@ -163,6 +163,7 @@ options = Option.common ++
 		"skip files smaller than a size"
 	, Option ['T'] ["time-limit"] (ReqArg Limit.addTimeLimit paramTime)
 		"stop after the specified amount of time"
+	, Option [] ["trust-glacier"] (NoArg (Annex.setFlag "trustglacier")) "Trust Amazon Glacier inventory"
 	] ++ Option.matcher
   where
 	setnumcopies v = Annex.changeState $

Remote/Glacier.hs

@@ -0,0 +1,235 @@
+{- Amazon Glacier remotes.
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Remote.Glacier (remote) where
+
+import qualified Data.ByteString.Lazy.Char8 as L
+import qualified Data.Map as M
+import System.Environment
+
+import Common.Annex
+import Types.Remote
+import Types.Key
+import qualified Git
+import Config
+import Remote.Helper.Special
+import Remote.Helper.Encryptable
+import qualified Remote.Helper.AWS as AWS
+import Crypto
+import Creds
+import Annex.Content
+import qualified Annex
+
+type Vault = String
+type Archive = FilePath
+
+remote :: RemoteType
+remote = RemoteType {
+	typename = "glacier",
+	enumerate = findSpecialRemotes "glacier",
+	generate = gen,
+	setup = glacierSetup
+}
+
+gen :: Git.Repo -> UUID -> Maybe RemoteConfig -> Annex Remote
+gen r u c = do
+	cst <- remoteCost r expensiveRemoteCost
+	return $ gen' r u c cst
+gen' :: Git.Repo -> UUID -> Maybe RemoteConfig -> Int -> Remote
+gen' r u c cst =
+	encryptableRemote c
+		(storeEncrypted this)
+		(retrieveEncrypted this)
+		this
+  where
+	this = Remote {
+		uuid = u,
+		cost = cst,
+		name = Git.repoDescribe r,
+ 		storeKey = store this,
+		retrieveKeyFile = retrieve this,
+		retrieveKeyFileCheap = retrieveCheap this,
+		removeKey = remove this,
+		hasKey = checkPresent this,
+		hasKeyCheap = False,
+		whereisKey = Nothing,
+		config = c,
+		repo = r,
+		localpath = Nothing,
+		readonly = False,
+		remotetype = remote
+	}
+
+glacierSetup :: UUID -> RemoteConfig -> Annex RemoteConfig
+glacierSetup u c = do
+	c' <- encryptionSetup c
+	let fullconfig = c' `M.union` defaults
+	genVault fullconfig u
+	gitConfigSpecialRemote u fullconfig "glacier" "true"
+	setRemoteCredPair fullconfig (AWS.creds u)
+  where
+	remotename = fromJust (M.lookup "name" c)
+	defvault = remotename ++ "-" ++ fromUUID u
+	defaults = M.fromList
+		[ ("datacenter", "us-east-1")
+		, ("vault", defvault)
+		]
+
+store :: Remote -> Key -> AssociatedFile -> MeterUpdate -> Annex Bool
+store r k _f _p
+	| keySize k == Just 0 = do
+		warning "Cannot store empty files in Glacier."
+		return False
+	| otherwise = do
+	src <- inRepo $ gitAnnexLocation k
+	storeHelper r k src
+
+storeEncrypted :: Remote -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
+storeEncrypted r (cipher, enck) k _p = 
+	-- With current glacier-cli UI, have to encrypt to a temp file.
+	withTmp enck $ \tmp -> do
+		f <- inRepo $ gitAnnexLocation k
+		liftIO $ encrypt cipher (feedFile f) $
+			readBytes $ L.writeFile tmp
+		storeHelper r enck tmp
+
+{- Glacier cannot store empty files. So empty keys are handled by
+ - doing nothing on storage, and re-creating the empty file on retrieve. -}
+storeHelper :: Remote -> Key -> FilePath -> Annex Bool
+storeHelper r k file = do
+	showOutput
+	glacierAction r
+		[ Param "archive"
+		, Param "upload"
+		, Param "--name", Param $ archive r k
+		, Param $ remoteVault r
+		, File file
+		]
+
+retrieve :: Remote -> Key -> AssociatedFile -> FilePath -> Annex Bool
+retrieve r k _f d = retrieveHelper r k d
+
+retrieveCheap :: Remote -> Key -> FilePath -> Annex Bool
+retrieveCheap _ _ _ = return False
+
+retrieveEncrypted :: Remote -> (Cipher, Key) -> Key -> FilePath -> Annex Bool
+retrieveEncrypted r (cipher, enck) _k d = do
+	withTmp enck $ \tmp -> do
+		ok <- retrieveHelper r enck tmp
+		if ok
+			then liftIO $ decrypt cipher (feedFile tmp) $
+				readBytes $ \content -> do
+					L.writeFile d content
+					return True
+			else return False
+
+retrieveHelper :: Remote -> Key -> FilePath -> Annex Bool
+retrieveHelper r k file = do
+	showOutput
+	ok <- glacierAction r
+		[ Param "archive"
+		, Param "retrieve"
+		, Param "-o", File file
+		, Param $ remoteVault r
+		, Param $ archive r k
+		]
+	unless ok $
+		showLongNote "Recommend you wait up to 4 hours, and then run this command again."
+	return ok
+
+remove :: Remote -> Key -> Annex Bool
+remove r k = glacierAction r
+	[ Param "archive"
+	, Param "delete"
+	, Param $ remoteVault r
+	, Param $ archive r k
+	]
+
+checkPresent :: Remote -> Key -> Annex (Either String Bool)
+checkPresent r k = do
+	showAction $ "checking " ++ name r
+	go =<< glacierEnv (fromJust $ config r) (uuid r)
+  where
+	go Nothing = return $ Left "cannot check glacier"
+	go (Just env) = do
+		{- glacier checkpresent outputs the archive name to stdout if
+		 - it's present. -}
+		v <- liftIO $ catchMsgIO $ 
+			readProcessEnv "glacier" (toCommand params) (Just env)
+		case v of
+			Right s -> do
+				let probablypresent = key2file k `elem` lines s
+				if probablypresent
+					then ifM (Annex.getFlag "trustglacier")
+						( return $ Right True, untrusted )
+					else return $ Right False
+			Left e -> return $ Left e
+
+	params =
+		[ Param "archive"
+		, Param "checkpresent"
+		, Param $ remoteVault r
+		, Param $ archive r k
+		]
+
+	untrusted = do
+		showLongNote $ unlines
+			[ "Glacier's inventory says it has a copy."
+			, "However, the inventory could be out of date, if it was recently removed."
+			, "(Use --trust-glacier if you're sure it's still in Glacier.)"
+			, ""
+			]
+		return $ Right False
+
+glacierAction :: Remote -> [CommandParam] -> Annex Bool
+glacierAction r params = do
+	when (isNothing $ config r) $
+		error $ "Missing configuration for special remote " ++ name r
+	runGlacier (fromJust $ config r) (uuid r) params
+
+runGlacier :: RemoteConfig -> UUID -> [CommandParam] -> Annex Bool
+runGlacier c u params = go =<< glacierEnv c u
+  where
+	go Nothing = return False
+	go (Just env) = liftIO $
+		boolSystemEnv "glacier" (datacenter:params) (Just env)
+
+	datacenter = Param $ "--region=" ++
+		(fromJust $ M.lookup "datacenter" c)
+
+glacierEnv :: RemoteConfig -> UUID -> Annex (Maybe [(String, String)])
+glacierEnv c u = go =<< getRemoteCredPair "glacier" c creds
+  where
+	go Nothing = return Nothing
+	go (Just (user, pass)) = do
+		env <- liftIO getEnvironment
+		return $ Just $ (uk, user):(pk, pass):env
+
+	creds = AWS.creds u
+	(uk, pk) = credPairEnvironment creds
+
+remoteVault :: Remote -> Vault
+remoteVault = vault . fromJust . config
+
+vault :: RemoteConfig -> Vault
+vault = fromJust . M.lookup "vault"
+
+archive :: Remote -> Key -> Archive
+archive r k = fileprefix ++ key2file k
+  where
+	fileprefix = M.findWithDefault "" "fileprefix" $ fromJust $ config r
+
+-- glacier vault create will succeed even if the vault already exists.
+genVault :: RemoteConfig -> UUID -> Annex ()
+genVault c u = unlessM (runGlacier c u params) $
+	error "Failed creating glacier vault."
+  where
+	params = 
+		[ Param "vault"
+		, Param "create"
+		, Param $ vault c
+		]

Remote/Helper/AWS.hs

@@ -0,0 +1,21 @@
+{- Amazon Web Services common infrastructure.
+ -
+ - Copyright 2011,2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Remote.Helper.AWS where
+
+import Common.Annex
+import Creds
+
+creds :: UUID -> CredPairStorage
+creds u = CredPairStorage
+	{ credPairFile = fromUUID u
+	, credPairEnvironment = ("AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY")
+	, credPairRemoteKey = Just "s3creds"
+	}
+
+setCredsEnv :: CredPair -> IO ()
+setCredsEnv p = setEnvCredPair p $ creds undefined

Remote/List.hs

@@ -32,6 +32,7 @@ import qualified Remote.Web
 #ifdef WITH_WEBDAV
 import qualified Remote.WebDAV
 #endif
+import qualified Remote.Glacier
 import qualified Remote.Hook
 
 remoteTypes :: [RemoteType]
@@ -47,6 +48,7 @@ remoteTypes =
 #ifdef WITH_WEBDAV
 	, Remote.WebDAV.remote
 #endif
+	, Remote.Glacier.remote
 	, Remote.Hook.remote
 	]
 

Remote/S3.hs

@@ -5,7 +5,7 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module Remote.S3 (remote, setCredsEnv) where
+module Remote.S3 (remote) where
 
 import Network.AWS.AWSConnection
 import Network.AWS.S3Object
@@ -22,6 +22,7 @@ import qualified Git
 import Config
 import Remote.Helper.Special
 import Remote.Helper.Encryptable
+import qualified Remote.Helper.AWS as AWS
 import Crypto
 import Creds
 import Meters
@@ -84,7 +85,7 @@ s3Setup u c = handlehost $ M.lookup "host" c
 
 	use fullconfig = do
 		gitConfigSpecialRemote u fullconfig "s3" "true"
-		setRemoteCredPair fullconfig (s3Creds u)
+		setRemoteCredPair fullconfig (AWS.creds u)
 
 	defaulthost = do
 		c' <- encryptionSetup c
@@ -261,28 +262,13 @@ s3ConnectionRequired c u =
 	maybe (error "Cannot connect to S3") return =<< s3Connection c u
 
 s3Connection :: RemoteConfig -> UUID -> Annex (Maybe AWSConnection)
-s3Connection c u = go =<< getRemoteCredPair c creds
+s3Connection c u = go =<< getRemoteCredPair "S3" c (AWS.creds u)
   where
-	go Nothing = do
+	go Nothing = return Nothing
-		warning $ "Set both " ++ s3AccessKey ++ " and " ++ s3SecretKey  ++ " to use S3"
-		return Nothing
 	go (Just (ak, sk)) = return $ Just $ AWSConnection host port ak sk
 
-	creds = s3Creds u
-	(s3AccessKey, s3SecretKey) = credPairEnvironment creds
-
 	host = fromJust $ M.lookup "host" c
 	port = let s = fromJust $ M.lookup "port" c in
 		case reads s of
 		[(p, _)] -> p
 		_ -> error $ "bad S3 port value: " ++ s
-
-s3Creds :: UUID -> CredPairStorage
-s3Creds u = CredPairStorage
-	{ credPairFile = fromUUID u
-	, credPairEnvironment = ("AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY")
-	, credPairRemoteKey = Just "s3creds"
-	}
-
-setCredsEnv :: (String, String) -> IO ()
-setCredsEnv creds = setEnvCredPair creds $ s3Creds undefined

Remote/WebDAV.hs

@@ -321,13 +321,7 @@ noProps :: XML.Document
 noProps = XML.parseText_ XML.def $ LT.pack "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<propertyupdate/>"
 
 getCreds :: RemoteConfig -> UUID -> Annex (Maybe CredPair)
-getCreds c u = maybe missing (return . Just) =<< getRemoteCredPair c creds
+getCreds c u = getRemoteCredPair "webdav" c (davCreds u)
-  where
-	creds = davCreds u
-	(loginvar, passwordvar) = credPairEnvironment creds
-	missing = do
-		warning $ "Set both " ++ loginvar ++ " and " ++ passwordvar ++ " to use webdav"
-		return Nothing
 
 davCreds :: UUID -> CredPairStorage
 davCreds u = CredPairStorage

debian/changelog

@@ -1,6 +1,6 @@
 git-annex (3.20121113) UNRELEASED; urgency=low
 
-  * New webdav special remotes.
+  * New webdav and Amazon glacier special remotes.
   * Show error message to user when testing XMPP creds.
   * Fix build of assistant without yesod.
   * webapp: The list of repositiories refreshes when new repositories are

doc/design/assistant/cloud.mdwn

@@ -15,7 +15,7 @@ More should be added, such as:
 * Box.com (it's free, and current method is hard to set up and a sorta
   shakey; a better method would be to use its API) **done**
 * Dropbox? That would be ironic.. Via its API, presumably.
-* [[Amazon Glacier|todo/special_remote_for_amazon_glacier]]
+* [[Amazon Glacier|todo/special_remote_for_amazon_glacier]] **done**
 * [nimbus.io](https://nimbus.io/) Fairly low prices ($0.06/GB);
   REST API; free software
 

doc/git-annex.mdwn

@@ -568,6 +568,17 @@ subdirectories).
   The repository should be specified using the name of a configured remote,
   or the UUID or description of a repository.
 
+* --trust-glacier-inventory
+
+  Amazon Glacier inventories take hours to retrieve, and may not represent
+  the current state of a repository. So git-annex does not trust that
+  files that the inventory claims are in Glacier are really there.
+  This switch can be used to allow it to trust the inventory.
+
+  Be careful using this, especially if you or someone else might have recently
+  removed a file from Glacier. If you try to drop the only other copy of the
+  file, and this switch is enabled, you could lose data!  
+
 * --backend=name
 
   Specifies which key-value backend to use. This can be used when
@@ -885,6 +896,11 @@ Here are all the supported configuration settings.
   Used to identify Amazon S3 special remotes.
   Normally this is automatically set up by `git annex initremote`.
 
+* `remote.<name>.glacier`
+
+  Used to identify Amazon Glacier special remotes.
+  Normally this is automatically set up by `git annex initremote`.
+
 * `remote.<name>.webdav`
 
   Used to identify webdav special remotes.

doc/special_remotes.mdwn

@@ -19,6 +19,7 @@ into many cloud services. Here are specific instructions
 for various cloud things:
 
 * [[tips/using_Amazon_S3]]
+* [[tips/using_Amazon_Glacier]]
 * [[tips/Internet_Archive_via_S3]]
 * [[tahoe-lafs|forum/tips:_special__95__remotes__47__hook_with_tahoe-lafs]]
 * [[tips/using_box.com_as_a_special_remote]]

doc/special_remotes/glacier.mdwn

@@ -0,0 +1,51 @@
+This special remote type stores file contents in Amazon Glacier.
+
+To use it, you need to have [glacier-cli](http://github.com/basak/glacier-cli)
+installed.
+
+The unusual thing about Amazon Glacier is the multiple-hour delay it takes
+to retrieve information out of Glacier. To deal with this, commands like
+"git-annex get" request Glacier start the retrieval process, and will fail
+due to the data not yet being available. You can then wait appriximately 
+four hours, re-run the same command, and this time, it will actually
+download the data.
+
+## configuration
+
+The standard environment variables `AWS_ACCESS_KEY_ID` and 
+`AWS_SECRET_ACCESS_KEY` are used to supply login credentials
+for Amazon. You need to set these only when running
+`git annex initremote`, as they will be cached in a file only you
+can read inside the local git repository.
+
+A number of parameters can be passed to `git annex initremote` to configure
+the Glacier remote.
+
+* `encryption` - Required. Either "none" to disable encryption (not recommended),
+  or a value that can be looked up (using gpg -k) to find a gpg encryption
+  key that will be given access to the remote, or "shared" which allows
+  every clone of the repository to access the encrypted data (use with caution).
+
+  Note that additional gpg keys can be given access to a remote by
+  rerunning initremote with the new key id. See [[encryption]].
+
+* `embedcreds` - Optional. Set to "yes" embed the login credentials inside
+  the git repository, which allows other clones to also access them. This is
+  the default when gpg encryption is enabled; the credentials are stored
+  encrypted and only those with the repository's keys can access them.
+
+  It is not the default when using shared encryption, or no encryption.
+  Think carefully about who can access your repository before using
+  embedcreds without gpg encryption.
+
+* `datacenter` - Defaults to "us-east-1".
+
+* `vault` - Glacier requires that vaults have a globally unique name, 
+  so by default, a vault name is chosen based on the remote name
+  and UUID. This can be specified to pick a valult name.
+
+* `fileprefix` - By default, git-annex places files in a tree rooted at the
+  top of the Glacier vault. When this is set, it's prefixed to the filenames
+  used. For example, you could set it to "foo/" in one special remote,
+  and to "bar/" in another special remote, and both special remotes could
+  then use the same vault.

doc/tips/using_Amazon_Glacier.mdwn

@@ -0,0 +1,69 @@
+Amazon Glacier provides low-cost storage, well suited for archiving and
+backup. But it takes around 4 hours to get content out of Glacier.
+
+Recent versions of git-annex support Glacier. To use it, you need to have
+[glacier-cli](http://github.com/basak/glacier-cli) installed.
+
+First, export your Amazon AWS credentials:
+
+        # export AWS_ACCESS_KEY_ID="08TJMT99S3511WOZEP91"
+        # export AWS_SECRET_ACCESS_KEY="s3kr1t"
+
+Now, create a gpg key, if you don't already have one. This will be used
+to encrypt everything stored in Glacier, for your privacy. Once you have
+a gpg key, run `gpg --list-secret-keys` to look up its key id, something
+like "2512E3C7"
+
+Next, create the Glacier remote.
+
+	# git annex initremote glacier type=glacier encryption=2512E3C7
+	initremote glacier (encryption setup with gpg key C910D9222512E3C7) (gpg) ok
+
+The configuration for the Glacier remote is stored in git. So to make another
+repository use the same Glacier remote is easy:
+
+        # cd /media/usb/annex
+        # git pull laptop
+        # git annex initremote glacier
+        initremote glacier (gpg) ok
+
+Now the remote can be used like any other remote.
+
+        # git annex move my_cool_big_file --to glacier
+        copy my_cool_big_file (gpg) (checking glacier...) (to glacier...) ok
+
+But, when you try to get a file out of Glacier, it'll queue a retrieval
+job:
+
+	# git annex get my_cool_big_file
+	get my_cool_big_file (from glacier...) (gpg)
+	glacier: queued retrieval job for archive 'GPGHMACSHA1--862afd4e67e3946587a9ef7fa5beb4e8f1aeb6b8'
+	  Recommend you wait up to 4 hours, and then run this command again.
+	failed
+
+Like it says, you'll need to run the command again later. Let's remember to
+do that:
+
+	# at now + 4 hours
+	at> git annex get my_cool_big_file
+
+Another oddity of Glacier is that git-annex is never entirely sure
+if a file is still in Glacier. Glacier inventories take hours to retrieve,
+and even when retrieved do not necessarily represent the current state.
+
+So, git-annex plays it safe, and avoids trusting the inventory:
+
+	# git annex copy important_file --to glacier
+	copy important_file (gpg) (checking glacier...) (to glacier...) ok
+	# git annex drop important_file
+	drop important_file (gpg) (checking glacier...)
+	  However, the inventory could be out of date, if it was recently removed.
+	  (Use --trust-glacier-inventory if you're sure it's still in Glacier.)
+	
+	(unsafe) 
+	  Could only verify the existence of 0 out of 1 necessary copies
+
+Like it says, you can use `--trust-glacier-inventory` if you're sure
+Glacier's inventory is correct and up-to-date.
+
+See [[special_remotes/Glacier]] for details.

doc/tips/using_Amazon_S3.mdwn

@@ -2,7 +2,7 @@ git-annex extends git's usual remotes with some [[special_remotes]], that
 are not git repositories. This way you can set up a remote using say,
 Amazon S3, and use git-annex to transfer files into the cloud.
 
-First, export your S3 credentials:
+First, export your Amazon AWS credentials:
 
 	# export AWS_ACCESS_KEY_ID="08TJMT99S3511WOZEP91"
 	# export AWS_SECRET_ACCESS_KEY="s3kr1t"

doc/todo/special_remote_for_amazon_glacier.mdwn

@@ -18,8 +18,13 @@ run, or files to transfer, at that point.
 
 --[[Joey]]
 
+> [[done]]! --[[Joey]]
+
 -----
 
 > In the coming months, Amazon S3 will introduce an option that will allow customers to seamlessly move data between Amazon S3 and Amazon Glacier based on data lifecycle policies.
 
 -- <http://aws.amazon.com/glacier/faqs/#How_should_I_choose_between_Amazon_Glacier_and_Amazon_S3>
+
+>> They did, but it's IMHO not very useful for git-annex. It's rather
+>> intended to allow aging S3 storage out to Glacier. --[[Joey]]