Storage and Backup
Storage
There are different file systems with different lifetime and redundancy which you can use to store your data.
- your home directory
- This is your primary directory where all settings, your Mail and other important data is saved. It is mounted on every host to /home/YOUR_LOGIN. A backup is done nightly. This file system has an individual limit which you can check with the command 'df'. In change to earlier setups it has no soft limit which you can exceed for a few days.
- /tmp
- This is the counterpart to your home. It is located on the local disk and should be used for temporary data. Unused files are delete after 14 days.
- /home/work-itp
/home/work-itp2 - This directories is globally accessible and can be used by everyone for minor important data which are not worth to be backed up or simply to large for home. This files are not deleted, but if the disk is full we tell you to delete some files. It runs on an raid5 system, that means a disk failure will not result in data loss. It is also served by a dedicated machine (the old tantalos) and heavy load does not affect the home directories. If you want to use this space please create a sub directory with you login name.
- The new work-itp2 is powered by two Raid-Boxes, kindly provided the HRZ. They internally form a raid5 and are merged under the host to a raid0 (striping), which can be called a raid 50 and results in a disk throughput of near 2Gb/s. To give this performance to the network the host is connected with two Gigabit uplinks using channel bonding. Benchmarks with NFS has shown that we do not relay get much more performance than a 1Gb link. The reason is the the cpu's in the host are two weak. If we can get a stronger machine, this will be upgraded in the future.
Backup
Backups of the home directory and several other important system directories is done nightly.
- There are held 3 generations of a file.
- Overwritten files are stored for 90 days
- A deleted file is stored for 90 days
If you have delete some files and want them restored, please contact the system administrator.
