Amanda backup system
Amanda is an automated system for backing
up and recovering disk and file systems, that have been developed by the Univerity
of Maryland.
Amanda can be installed on multiple platforms, it runs over a network, so a
single amanda server can backup multiple workstations, and taking advantage
of Samba, it can
be used to backup disks over a Microsoft network.
Amanda runs along a cycle, after which the backup tapes are reused. It can
perform two types of backup:
- full only, where the files are saved only once per cycle;
- incremental, where the files are saved once, then new or modified files
are saved at every run.
Backup policy, as implemented at CSIM is as follow:
- backup run over three weeks cycle, no recovery can be made that is older
than three weeks;
- backup are starting at 00:45 on Tuesday to Saturday. Backup are run at
night to avoid loading the network during the day;
- user's files (including email) are backed up at each run, doing incremental
backup. A full backup of every user's files is done once per cycle;
- system files are saved in full backup type, only once per cycle;
- Microsoft Windows system will allow to save up to three shares in full type,
and up to two shares in incremental type. It can only backup directories
and does not offer any way to backup a complete hard disk;
- there is no way to know, nor to enforce the day when Amanda runs a full
backup of the user's files;
- backup is meant for disaster recovery, not for user's mistake recovery.
Given the fact that only one run is made per day, it is not realistic to ask
for recovering a deleted email that was received only hours ago, it had not
been backed up yet.
Note: limitation on the backup for Microsoft stations makes it necessary
that an agreement is obtained among the many users of a shared machine. Back
up will never work properly if one user decide to bak up one directory one day
and another user change it to another directory another day. A good way to proceed
would be to define a common directory called C:\users\ and to put individual
files in sub-directories. C:\users\ should them become the share to
backup.
Note: backup will only be performed if the computers are running at
the time of the backing up.
Backup of Unix server
This will be done on a case by case. Obviously, you must install Amanda client on the Unix system you intend to backup.