Demystifying the Linear Tape File System (LTFS)
Since the introduction of the Linear Tape File System (LTFS), a number of articles, white paper and tech briefs have been written about it and its impact on tape.
Let's look at the context around what the excitement is all about and discuss how LTFS is being used and deployed.
A file system for tape
To start, LTFS is just what is says it is – a
file system for linear tape. In simple terms, LTFS defines two partitions on the
tape:
- Partition 0 contains the list of files
and their location on the tape
- Partition 1 contains the actual files
This allows
the tape media to be “self-describing” in identifying each individual file on
the tape with direct access to each file. It allows for the creation of a
directory structure to make file management even easier. The specification for
LTFS is open and is controlled and managed by the
Storage Networking Industry
Association (SNIA). A number of
contributing members are working on the specification, including those from HP
and IBM, who ensure that future releases are interoperable with previous
versions and add new features to address the growing demand for LTFS.
Making tape as easy to access,
manage and share as disk
As a file system for tape, various tape
utilities have been developed allowing a tape drive to mount within an operating
system (Windows, Linux, and MAC), thereby allowing for basic file system
operations such as directory creation and drag and drop to move files to and
from the tape drive. The specification ensures that media written by one file
system (i.e. Windows) can be read by another file system (i.e. Mac). Now a user
can use a tape drive like a large thumb drive. Just like a thumb drive, LTO
tapes can be used to share data between systems or can provide a place to store
data for safekeeping. HP provides a set of utilities known as
HP StoreOpen to simplify the
use of tape with LTFS. HP StoreOpen Standalone provides a GUI to mount a
standalone tape drive and format a tape with LTFS. HP StoreOpen Automation
mounts an HP StoreEver tape library and presents each tape cartridge in the
library as an individual file folder, automatically moving tapes in and out of
the tape drives as you read/write to a given tape folder.
The value of LTFS for archive
Because LTFS is an open format, content stored
on LTFS-formatted tapes can be read by any application that has support for
LTFS. This makes LTO with LTFS an ideal solution for long-term archive. A number
of advanced archiving solutions available today have integrated LTFS into their
product offerings. These solutions provide many more features above and beyond
basic tape access such as tape duplication, media tracking, meta data management
and often employ some sort of disk cache/buffer to optimize tape access. One
such solution is
HP StoreEver Tape as NAS , which combines the access
benefits of NAS with the cost, reliability and long-term retention benefits of
tape. With these solutions, you can leverage the cost efficiencies of tape and
avoid vendor lock-in to retrieve your data down the road.
HP have partnered with a number of LTFS
archive solution providers to ensure interoperability with HP StoreEver
products. HP StoreOpen
is a great supplementary solution as it can be used to read tapes exported from
these advanced solutions without having to install the solution software
product.
The growing ecosystem for LTFS
solutions
LTFS has provided new opportunities to add
tape to existing software solutions without the need to become tape experts.
Using the open source code and
HP StoreOpen
solutions available from HP, developers can quickly and easily add tape and tape
library support to their software products. This has generated a number of new
product offerings that were not available just a few years ago.
Changing the game for data
exchange and archive
The Linear Tape File System is a true game
changer. It’s an open file system for tape, managed and supported by SNIA by
leading hardware and software companies like HP giving it credibility and
long-term support. From basic drag and drop access to full-featured solutions,
users can benefit from LTFS as a multi-vendor data transport and/or long-term
archive solution. Combined with the
HP StoreEver LTO tape drives and tape
libraries, you have a solution that is cost effective,
reliable and built on open standards—and that is the perfect combination for
long-term archive.