Extended attributes

How IBM Spectrum Archive™ uses extended attributes.

Spectrum Archive supports valid characters in W3C Extensible Markup Language (XML) 1.0 standard, except for the / (slash) and : (colon), for extended attribute names. A file can have multiple extended attributes. The maximum size of an extended attribute is 4 KB. When the value of an extended attribute includes binary data, Spectrum Archive encodes the data in base64.

On Linux and Windows, all extended attribute names that start with the prefix "ltfs" with any capitalization are reserved for virtual extended attributes. Refer to the topic Virtual extended attributes.

Linux

Linux supports restrictive naming for extended attributes. Each extended attribute begins with one of the following names and ends with a period:
  • system.
  • security.
  • trusted.
  • user.
Note: For security purposes, only user.* extended attributes can be modified.

Windows

Windows supports restrictive naming for extended attributes. Windows allows only 8-bit ASCII characters that do not contain any of the following characters:
  • ASCII values 0x0000 – 0x001F
  • \ / : * ? " < > | , + = [ ] ;
Note: If any of these characters are used on Linux, and the medium is moved from that system to Windows, the attributes do not display.