Data archiving and distribution of the Virgo antenna for gravitational wave detection

We describe the architecture of the data archiving and distribution of the Virgo antenna for gravitational wave detection. The main characteristic of this system is the modularity of the architecture. This solution allows system upgrades without dramatic changes of the hardware and software components. The main performances are: 1. Maximum sustained data flow of 10 Mbyte/s on DLT tapes (35/70 Gbyte) for the raw data archiving; 2. Up to 1 Tbyte data archiving capacity on disk at a maximum sustained data flow of 25 Mbyte/s for the online data distribution; 3. Up to 10 Mbyte/s data retrieval flow for the on-line data distribution. The basic architecture of the system consists of two sections: an acquisition and storage section and a data management section. The former is a LynxOS based system with the disks directly connected to the CPU slave boards, the latter is a DEC-Unix Alpha Server (Data Server), NFS mounting the LynxOS disks through a Fast Ethernet network.