1File Services Daemon 2==================== 3 4Please note, this section is somewhat out of date as the code has 5evolved significantly. The basic idea has not changed though. 6 7This chapter is intended to be a technical discussion of the File daemon 8services and as such is not targeted at end users but rather at 9developers and system administrators that want or need to know more of 10the working details of **Bareos**. 11 12The **Bareos File Services** consist of the programs that run on the 13system to be backed up and provide the interface between the Host File 14system and Bareos – in particular, the Director and the Storage 15services. 16 17When time comes for a backup, the Director gets in touch with the File 18daemon on the client machine and hands it a set of “marching orders” 19which, if written in English, might be something like the following: 20 21OK, **File daemon**, it’s time for your daily incremental backup. I want 22you to get in touch with the Storage daemon on host archive.mysite.com 23and perform the following save operations with the designated options. 24You’ll note that I’ve attached include and exclude lists and patterns 25you should apply when backing up the file system. As this is an 26incremental backup, you should save only files modified since the time 27you started your last backup which, as you may recall, was 282000-11-19-06:43:38. Please let me know when you’re done and how it 29went. Thank you. 30 31So, having been handed everything it needs to decide what to dump and 32where to store it, the File daemon doesn’t need to have any further 33contact with the Director until the backup is complete providing there 34are no errors. If there are errors, the error messages will be delivered 35immediately to the Director. While the backup is proceeding, the File 36daemon will send the file coordinates and data for each file being 37backed up to the Storage daemon, which will in turn pass the file 38coordinates to the Director to put in the catalog. 39 40During a **Verify** of the catalog, the situation is different, since 41the File daemon will have an exchange with the Director for each file, 42and will not contact the Storage daemon. 43 44A **Restore** operation will be very similar to the **Backup** except 45that during the **Restore** the Storage daemon will not send storage 46coordinates to the Director since the Director presumably already has 47them. On the other hand, any error messages from either the Storage 48daemon or File daemon will normally be sent directly to the Directory 49(this, of course, depends on how the Message resource is defined). 50 51Commands Received from the Director for a Backup 52------------------------------------------------ 53 54To be written … 55 56Commands Received from the Director for a Restore 57------------------------------------------------- 58 59To be written … 60