The new role of LTO-5: LTFS vs. tar HPA Tech Retreat Palm Springs February 17, 2011 ©2011 Cache-A...

The new role of LTO-5:

LTFS vs. tarHPA Tech RetreatPalm SpringsFebruary 17, 2011

©2011 Cache-A Corporation

The issues with using tape Data Portability

Standard for format on tape

Ease of Use Command-line vs. GUI

Self-Describing Directory of a tape’s contents

Linear Nature Not random access

Can’t freely delete content and recover space ©2011 Cache-A Corporation #2

Data Portability

The majority of tape-based solutions use proprietary formats

Only one open format has been available – tar

LTFS now adds a second open format

HP & IBM Interop proven in the demo room

©2011 Cache-A Corporation #3

Ease of Use

tar has been command-line driven and mostly limited to tech-weenies

LTFS offers accessibility from normal file tools including: Windows Explorer

Mac OSX Finder

©2011 Cache-A Corporation #4

Self-Describing Tape – a bit of history 1987: SuperMac DataStream (Mac) 1992: QIC with QFA (DOS) 1996: DatMan (Windows)

2004-2007: Quantum A-Series (networked)

2008: Cache-A tar (networked)

2010: LTFS (Linux, Mac, Windows)

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Proprietary

File AccessProprietary

Format on Tape

Open

File SystemOpen

Format on Tape

Proprietary

Table of

ContentsOpen

Format on Tape

LTO (2000)

tar – a bit of history Originally in Unix in the late 1970’s

tape archive

Established POSIX.1-1988 standard in 1988 POSIX.1-2001 revised extended tar a.k.a. “pax” format

Unlimited pathname length

Unlimited character set encoding

Date/Time, Symlink, User/Group improvements

Mac, Windows, Unix and Linux versions available

©2011 Cache-A Corporation #6

Open

Mature

OS

Independent

NOT

Self-Describing

NOT

Easy-to-use

tar Format

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tarball

Cache-A tar Format

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CatalogDatabase

TOCTOCTOCTOCTOC

Cache-A Appliance Disk

AdditionalMetadata

LTFS Format

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LTFS Format

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Cache-A LTFS Format

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Catalog

TOCTOCTOCTOCTOC

Cache-A Appliance DiskAdditional

Metadata

TOC

LTFS Issues

Newly Minted, work to be done Not all file names supported

Tape spanning not supported

LTO-5 Only

Long delays to update index upon eject

Many ops cause tape thrashing ©2011 Cache-A Corporation #12

LTFS does not work like a hard disk

The Good News: LTFS Looks like Disk The Bad News: LTFS Looks like Disk If you treat it like Disk, you will have problems

File fragmentation, performance issues

i.e. Auto-Save

Multi-file operations

i.e. Icon View

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Cache-A LTFS implementation

Include Cache-A TOC on tape

Include TOC in Catalog

Include “URL encoding” to support real-world file naming

Handle linear transactions behind the scenes

Plans for continued future enhancements

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Format Comparison

Portable, Cross Platform

Self-Describing

Easy-to-Use

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LTFS tar tar LTFSbaseline Cache-

A

Format Comparison

Single File Restore

Multi-tape Volumes

Library Option

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LTFS tar tar LTFSbaseline Cache-

A

Format Comparison

Networked, Multi-user

No Client-side Software

Handles all file names

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LTFS tar tar LTFSbaseline Cache-

A

Format Comparison

Multi-tape Search

Search Restore

Technical Support

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LTFS tar tar LTFSbaseline Cache-

A

Summary

LTFS is the only Self-Describing, Open Solution Available

tar is More Mature and More Ubiquitous but not Self-Describing or Easy-to-use

Appliance implementations like Cache-A’s can improve both – neither is complete on their own

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Thank You

©2011 Cache-A Corporation #20