• What happens if you delete accidentally some (all) files of your directory ?
• What happens if you want to recover a file that you deleted/changed 2 weeks ago or more ?
• What happens if your workstation stop working ?
• What happens if the File Server stop working ?
• What happens if a disk stop working ?
• What you have to do in order to backup your data?

In order to answer to these questions, we prepared some systems (hardware and software) that save/backup/move our data in an automatic fashion. This way the human intervention (and so the possibility of error) is reduced at the minimum.

Remember that when we say home directory, we talk about your homedirs stored on the file server, we don't do backup of workstations or laptops.
For some suggestion on how to backup your laptop see here.
If a workstation stop working is not a problem, we can repair/substitute the workstation without loss of important data. In case of Personal Laptops we don't offer any kind of safeguard, regarding data stored on the laptop's disk.

The most important thing that humans and computer share is just one: the data recorded in memory. No matter what kind of computer, interface, network connection or whatever else mechanical/logical device users can/must use: if they can't access their data (stored inside the computer), problem arise. For a user isn't important where or how the data are saved, the only important thing is that hi/her needs access to these data, even in case of his/hers fault or in case of technical problems (yes, earthquake and flood are just technical problems).

To offer the maximum support to users, our Network has different method to backup the data. Each method has pros and cons, and not all the method are accessible directly to the users. In some cases the user must ask to the System Administrators to recover his/hers data from the backup devices. This is necessary to maintain a good level of compromise between access to data and security. The backups are complete collections of all the data that all users collect and thus we have to consider the access to these repositories carefully.
We have 3 different level of backup that offer access to deleted/changed files with different solutions.

• Backup in the .snapshot directory
• Backup on Hard Disk in a central backup sever
• Backup on Tape cartridge in central backup server

Every user can find inside his/hers homedir on the central filer an hidden directory named .snapshot. Inside this directory exists others directories that have name

• hourly.[0-3]
• nightly.[0-3]
• weekly.[0-1]

As the name suggest, these directory contain the file changed during the lasts 4 hours, 4 days and 2 weeks (the 0 is something). If the wanted file was deleted/changed during this time, the user have to search these directories, in order to find it. Pay attention that inside the .snapshot directories a user can see the state of his/hers directory how it was, so if you look inside one of these directory you can see not only the files changed, but all the files you have currently. Amazing, isn'it? If the searched file is found, the users can copy it where it want and the restore is done.

Every day at 00.30 a backup process copies all the files present in the users directories to another server, accessible only to System Administrators. Stored in this server we maintain the last 30 days of all the homedir, so in case of failure of the central file server we can restart with only 1 day of lost. Not vital files aren't backed up. here you can find the list of files excluded.
To retrieve a file from this server the user must ask it to System Administrators, and please don't forget the details about the file.

Every day there's a backup procedure that copies all the files changed during the day to a tape cartridge stored on the central server of Epfl. Every Sunday night, the backup's procedure do a copy of all the files present on our File Server.
To access the files stored on tapes the user must ask to the System Administrator that forward his/hers request to the backup team of the Epfl. The restore of files from tape require a lot of time, but normally is done during the day of request. The tapes are cheaper than the hard disk (and more slower) so we can maintain the data for more time. Currently we can restore the last 3 months of data, from tape backups.

Laptops are the nightmare of any system-manager. Not only they are always a special case, therefore taking the same amount of work as 50 identical workstations, but also (and more importantly), their backup is under the only responsability of the user. The files on a laptop are much more in danger than those on a workstation or on a file server: the laptop HardDisk is smaller and more fragile, the laptop can get stolen or lost, laptops get into many different uncontrolled networks…. Nevertheless, we know that very few users backup their data on a regular basis. As Laptops become more and more convinient to use, the important work data also becomes more and more in danger. It is useless to have a sophisticated centralized backup system as the one described above if users keep their important data on their laptop. So please backup your work data as often as possible. Afterall, your work data belongs to EPFL.

Please refer to this page for more informations about backup of laptops