Backup devices

MetaCentrum currently uses tape library NEO8000 from Overland Storage with 500 tape positions based on the LTO-3 technology where each tape has an uncompressed capacity of 400 GB (this system replaced long time existing backup and archive system – a tape library with on-line uncompressed capacity of 12 TB). There are two fully functional equivalent libraries with a total on-line capacity of 400 TB uncompressed data available now!

Each library has four Hewlett-Packard Ultrium 3 tape drives and one robotic mechanism for tape exchange. A backup server (dual CPU AMD Opteron with 4 GB RAM) is attached to each library through three SCSI Ultra320 channels. One library is located at the University of West Bohemia and the second at Masaryk University. A combination of EMC Legato NetWorker with home-developed software (the replacement of the Autochanger module, see below) manages both libraries.

The server at the University of West Bohemia with an 8 TB disk array EasySTOR 1606PSA serves as an auxiliary cache that allows to use the tape library with the maximum transfer speed even in the case when the data delivery over the network is uneven (the lifetime of the library drives and tapes degrades when the tapes must be often stopped and restarted due to the slow data delivery; it also has a negative impact on the total available tape capacity). A similar disk array will be attached to the second tape library in Brno too.

We developed a software replacement for the Legato NetWorker Autochanger module that is necessary for running the tape library in the MetaCentrum environment. Own development as an alternative to purchasing the module was chosen in order to have a more flexible solution capable of adding specific extension for media management. Such extensions are very hard or even impossible to integrate with the Autochanger module. We plan to develop this software solution further by including a new function for monitoring the state of the tape drivers and media (failures, usage history etc.).

The existing distributed backup environment provides a robust and fault-tolerant solution that could survive even “catastrophic” events such as a complete crash of one of the MetaCentrum sites.

Available storage capacities provide possibility to regularly perform backup of users home folders at cluster frontends as well as offer ad hoc archiving of specific users data. In the case of your interest of archiving service, please, contact MetaCentrum administrators using address meta@cesnet.cz.