Synology is providing a Glacier backup tool which seems to be an easy way to backup data on the low cost amazon solution. I will not describe how to configure it a log of blogs are doing it and I do not like to be redundant. The question I did not find an easy answer was : will I be able to restore my backup even if my synology crashed and I would not be able to get one other…
To answer this question I started by creating my backup and then access to my data. What you firstly have to know is that Glacier is built for backuping data your should not have to restore (I mean you hope to not have to restore later). Practically it means that accessing your backup is a long way. The first point is that you can’t get an instantaneous access to your data and have to way a 24h batch to be able to retrieve a listing. Then if you want to download a file, everything is asynchronous with a long wait. That is to say, this was a long way to get the result I’ll tell you next !
So, let’s back on the question : how can I retrieve my backup manually ?
Synology is storing the backup into two vaults, the first one is containing all the files with really long and random name in a flat directory. So if your backup as myne is 16K files, you will found 16K files in this vault. These files are not encrypted, they are just renames. My opinion this that synology should provide a pgp encryption option for this backup ! On s3 you have a native encryption, on glacier not, meaning you have to trust Amazon on disk/tape cleaning before destruction if you do not want your data out of control ( and also easily accessible by NSA eyes ). By-the-way, the advantage of this is that it will be easy to restore. The main issue will be about the location of the files and the initial name and extension restore.
This is the reason of the second vault. This one is containing (as much as I have seen during my test) only one file. This file is catalog. The file is a SQLite file containing different tables. The main one is the list of the backup file with Glacier random name associated to original full path name. It will be easy to use it to create a custom script and automate the move process in a manual restore operation. This file can easily be opened for a quick look using SQLite Manager addon on Firefox for example.
So, to conclude, is it possible to manually restore a synology glacier backup, the answer is yes. Will it be easy ? the answer is acceptable. Are the data protected on glacier ? the answer depends if you trust Amazon or not.