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To better understand LTFS (Linear Tape File System) and what it has to offer, Rainer Richter, MTMP’s head of software development and integration and a former member of IBM’s LTFS development team, has written a white paper "LTFS, E-mancipation for Tape" available on request.
In summary, LTFS is a non-proprietary, free, ‘open source’ system that can make a single LTO-5 tape drive as easy to use as a removable hard drive. LTFS formatted tapes have two partitions, one for the files (media essence) and another that contains an index (coded in human-readable XML) describing the files, optionally with extended attributes or metadata and their locations on the tape. Thus LTFS tapes are self-describing of their content like a removable hard drive or flash drive and, without the requirement for proprietary software, can be read by any other LTFS/LTO-5 drive (a particularly high value feature in disaster recovery and interchange scenarios.) In a basic sense, the LTFS index partition echoes the function of the time-code track on professional video-tape and it can be used in a similar fashion to access individual files (shots or frames) on tape unlike TAR or TAR-like approaches.
One of the key benefits of LTFS is it makes data tapes interchangeable between all LTO-5 drive users that implement LTFS. This interchangeability is due to the LTFS partitioned tape format specification being locked in by the various manufacturers of the drives (The Ultrium Consortium: HP, IBM
and Quantum). The other key component is the file system which provides the basic disk-like functionality. By implementing the LTFS tape format,
with or without using LTFS file system code, solution developers can
enhance their particular applications, solutions or appliances to take advantage of the lower costs of data-tape vs. hard disk drive or solid-state memory. (According to the Clipper Research Group, “disk is more than 15 times more expensive than tape and uses 238 times more energy.” http://www.lto.org/News/whitepapers-presentations.html ... ‘Tape Delivers Significant TCO Advantage over Disk’)
LTFS in its simplest form for a single drive can deliver the same basic functions as a disk-drive when connected to a workstation or server, but of course, in a linear manner. New files are appended at the end of previously written files. Files are found using a byte-offset location on the tape and then read. This is very analogous to how professional video tape is used including the ability to search for a frame of video using time code. For higher-value, more complex applications which might utilize large robotic tape libraries, developers have and are building solutions and appliances on LTFS to take advantage of its features and benefits. Here is a list of use-case requirements that can be met with LTFS solutions available today or very soon:
> Extending or backing up SAN or NAS capacity with lower cost, more durable
and more robust LTO tape solutions… (these include media specific SANs
for AVIDs or FCPs or more generic ones like Isilon)
> Network Attached Storage (appears as a NAS appliance to users but it is
primarily an LTFS/LTO-5 library using a low percentage of disks)
> Disaster Recovery (made more effective with self-describing content)
> Digital media essence distribution system to support file-based broadcast
play-out operations or production workflows for VFXs or digital animation
(similar to HSM data movers for media files)
> On-set capture and backup of digital cameras
> File-base transcoding, editing and DI workflow systems Professional VCR
replacement.
Our firm, MTMP, is able to offer many of these LTFS enabled products for the above use-cases. Please let us know if you would like to know more about them or would like to explore how LTFS might benefit your business.
Useful LTFS Websites:
> LTO Project: www.lto.org/technology/ltfs.html
> HP LTFS: http://h71028.www7.hp.com/enterprise/us/en/solutions/storage-linear-tape-file-system.html
> IBM LTFS: www-03.ibm.com/systems/storage/tape/ltfs/
> Oracle (Sun/STK) oss.oracle.com/projects/ltfs/
> Quantum LTFS: www.quantum.com/Products/TapeDrives/LTOUltrium/LTO-5/LTFS/Index.aspx
