the new role of lto-5: ltfs vs. tar hpa tech retreat palm springs february 17, 2011 ©2011 cache-a...
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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
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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
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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
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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
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