- The server downloads ’urbackup/data/filelist.ub’ from the client. If it is an incremental backup the server compares the new ’filelist.ub’ with the last one from the client and calculates the differences.
- The server starts downloading files. If the backup is incremental only new and changed files are downloaded. If the backup is a full one all files are downloaded from the client.
- The server downloads the file into a temporary file. This temporary file is either in the urbackup_tmp_files folder in the backup storage dir, or, if you enabled it in the advanced settings, in the temporary folder. On successfully downloading a file the server calculates its hash and looks if there is another file with the same hash value. If such a file exists they are assumed to be the same and a hard link to the other file is saved and the temporary file deleted. If no such file exists the file is moved to the new backup location. File path and hash value are saved into the server database.
I do not understand why to waste Internet bandwitch, time and other … downloading the same file multiple times and delete it as duplicate.
Is there any chance to change it to download only new or changed files during full backup ??
I have 200 remote - Internet clients and it is really big issue for me and after reading this point:
7.4 File transfer over Internet
If a client is connected via Internet UrBackup automatically uses a bandwidth saving file transfer mode. This mode only transfers changed blocks of files and should therefore conserve bandwidth on files which are not changed completely, such as database files, virtual hard disks etc… This comes at a cost: UrBackup has to save hashes of every file. Those hashes are saved the folder “.hashes”. They are only saved if the Internet mode is enabled. If the hashes of a file are not present e.g. because Internet mode was just enabled, they are created from the files during the backup and may therefore slow down the backup process.
i thought it will work other way but now i stuck.
