As hard disc sizes have grown it has become economically feasible to move this third tier to disc storage, the issues then become the packing density (how much cooling can be applied to a given equipment volume) and the power consumption (disks use power, tapes don’t).
Since the disks are hermetically sealed with the the heads floating over the disk surface some of the mechanical issues associated with dirt and clogging of tape based systems are also avoided leading to very high reliability.
- Simple linking to Automation and Media Management system using existing drivers and protocols
- Can connect to an unlimited number of Alto shelves
- Replication to multiple disks inside Alto
- Manages the creation of a copy of content in a cloud storage system like Amazon S3
- Disk Lifecycle Management using pre-conditioning and S.M.A.R.T. monitoring of disks
- Web based user interface allows manual operation and monitoring
- All file transfers are verified by MD5 checksums
- Policy based replication and regeneration
- Provides both Virtual File System (NFS, CIFS, FTP) and File Transfer API for maximum flexibility
- Built in Web based documentation
Type A System
Type B System
File manager runs on an external server. This configuration can support up to 64 Alto main chassis each with expansion. This arrangement can provide greater throughput and by placing some of the Alto chassis remote from the installation offsite backup.
How it works
File Manager uses a database to provide the index and directory operations usually provided by a filesystem. When a file is opened for reading or writing the database is used to locate the file or allocate space for it if it is a new file. The appropriate disks are then powered up until no longer required. The database also stores an audit trail of all disk operations with their times. This together with the location data enables reports to be produced showing disk usage, spread of items, free storage etc.
Because Alto disks are used as direct file stores (no raid configurations) most installs will be set up to make multiple copies of a file. File manager makes these multiple copies simultaneously as the file is written, at the same time an MD5 checksum is calculated for the data and stored in the database. Whenever a linear read is made of a file the checksum is checked, any error will place the disk offline and fail the disk operation. The retry will then be sourced from the second copy of the file.
In File Manager systems set to make 2 copies of files a failed disk can be regenerated using the second copies of the files. This operation can be used either to regenerate the files onto the same disk after reformatting if the failure is considered temporary or onto a new disk.
Virtual File System
File Manager creates a virtual file system. The top level directories are the storage categories which determine storage policies (speed of transfer, number of copies kept etc). Below this any file hierarchy can be used enabling archiving of post production projects or integration with existing processes. Unlike most virtual file systems data access is directly to and from the Alto disks, there are no stub files and no intermediate raid store is used. This gives better system scaling and the assurance that a write that has been completed is secure and copied in the archive. The virtual file system can be shared by NFS, CIFS/SMB or FTP including FXP for media management systems. Checksums are used for all linear transfers to give data reassurance.
File Transfer API
File manager supports File transfer by API for control of transfers by external systems. It can simulate many popular archiving systems to simplify integration. In this mode full prioritised job control is available allowing a large batch of transfer requests to be handled in the most efficient way.
A multi-user web UI can be used to monitor and trigger transfers and reconfigure the system. The UI allows the SMART data from the disks to be monitored.