File management / Recovering a deleted file¶
Most of the users' files are stored on a file server, i.e. a specialized machine, with no computing capacity (denfert.polytechnique.fr is its name). Its capacity is 8TB
Access to files¶
From all CMAP Unix stations, a user accesses his files in the /home/login directory
Recovery of overwritten / deleted files¶
The server is secured at two levels:
- In case of a crash (failure) of one or more hard disks, the data are automatically rebuilt by the system. In case of crash of too many disks, of course, data will be lost!
- In case of a handling error (/bin/rm *), or for any other reason, it is possible to recover previous versions of its files.
- In each directory, there is an invisible subdirectory named .snapshot which contains the old versions (in fact, stored by difference, for obvious reasons of space).
- These versions are stored in subdirectories named hourly.x, nightly.x or weekly.x (x is a number between 0 and 7, 0 more recent than 1, ...).
- Find according to the dates (order
ls -ltr) the directory which interests you.
- From this directory, copy the desired file(s) to your native directory /home/login/...