Technical Note: XTN1601
Background
Alternate data streams, also known as "NTFS streams" and "named streams", are additional data streams that can be associated with a file. The relationship between a file and an alternate data stream is conceptually very similar to the relationship between a directory and a file; just as a directory can contain zero or more named files, a file can contain zero or more named alternate data streams. An alternate data stream is accessed by appending ":" (colon) and the stream name to the name of the file. Alternate data streams are supported by Windows NTFS volumes, Mac OS/X Server from version 10.5 and some NAS (Network Attached Storage) operating systems.
How XenData Manages Alternate Data Streams
Support for alternate data streams in XenData6 Server depends on the data cartridge format in use. The TAR (tape) cartridge format fully supports alternate data streams. The LTFS (tape) and ODA/UDF (optical) cartridge formats do not support alternate data streams because the underlying format specifications do not support alternate data streams. While it would technically be possible to support streams in the XenData implementation, attempting to do so has been found to break compatibility with other implementations of these file systems.
XenData6 Server from version 6.21 supports a range of commonly used alternate data streams by using Hidden File Group Policies to ensure that alternate data streams with common names are not written to the archive and do not cause errors with the LTFS and ODA file systems
Alternate Data Streams of the following types are excluded from the archive using the aforementioned hidden File Group policies:
- *:Zone.Identifier
- *:AFP_AfpInfo
- *:com.apple.metadata*
- *:com.apple.quarantine
- *:com.apple.TextEncoding
- *:com.apple.FinderInfo
It is possible to exclude streams of other types from being written to archive media by adding new File Group policies. Please contact Technical support if you require any further information.
Applicable Operating Systems
- Windows Server 2012 R2
- Windows Server 2016
- Windows Server 2019
Applicable XenData Software
This technical note is applicable to:
- Version 6 – Server Editions of Archive Series software
- Version 7 – Server Editions of Archive Series software including the Cloud File Gateway
PBS
XenData’s fully supported clustered server meets all the requirements for our disaster recovery site. We have been very pleased with the SX-525 product and XenData’s technical team who have provided system design and integration services above and beyond expectations.
James Cutright, Director, Project Management
PBS
Crew Cuts
I did my research, and the best archive solution was from XenData which manages a robotic LTO library behind the scenes. This helps to minimize our total costs and allows us to focus on producing great content for our customers.
Chris Keenan, CTO
Crew Cuts
Ideal Systems Singapore
We partnered with XenData for the GlobeCast Broadcast facility rollout, because it offers one of the most cost effective, robust digital video archives on the market and a great migration alternative to some of the more expensive digital video archive vendor offerings.
Fintan Mc Kiernan, CEO
Ideal Systems Singapore
North Shore Automation
Having completed over 25 joint installations of XenData archive systems, we have found everyone on the XenData team to be both highly professional and super responsive and their technology to be rock solid. They are truly a pleasure to work with.
Bryson Jones, Founder
North Shore Automation
This is Just a Test
With over 558 TB of content and growing, conventional backup solutions just don’t work for us. Our XenData system allows us to maintain an ongoing mirrored copy of our shared storage while creating replica LTO copies for offsite storage.
Nathan Flom
This is Just a Test
Excelencia
We have now installed over 170 XenData archive systems across Mexico and they have proven to be very reliable. In addition, the technical support from XenData has been outstanding.
Jorge Castaneda, President
Excelencia en Comunicaciones y Tecnología