FastGlacier File Metadata Format

As you probably know, Amazon Glacier doesn't support file names. Each file (an 'archive') has a unique ID and an optional description (an 'archive description').

FastGlacier and many other Amazon Glacier tools use archive description to store filenames and other metadata such as last modification time.

Unfortunately there is no single standard on storing metadata. FastGlacier supports most of the common metadata formats.

Below we will describe metadata format used by FastGlacier. This might be useful if you would like to write your own custom tool to restore files uploaded with FastGlacier.

If you are not developer, or do not want to write the code, check out these instructions: How to download files from Amazon Glacier

Metadata Format v4

The following metadata format is used from version 2.6.1:

ArchiveDescription =

  <m>
    <v>4</v>
    <p>path</p>
    <lm>utc-lastmodified</lm>
    <ce>compressed_flag:encrypted_flag:file_hash:file_size</ce>
  </m>
 
where:
 
  path = base64(utf8(file name))
 
  utc-lastmodified = "yyyyMMdd\\THHmmss\\Z"
  
  compressed_flag - "1" if file compressed and "0" otherwise
  
  encrypted_flag - "1" if file encrypted and "0" otherwise
  
  file_hash - an md5 hash of uncompressed/unencrypted file
  
  file_size - the size in bytes of uncompressed/unencrypted file
		

Example:

<m>
  <v>4</v>
  <p>Z2xhY2llci1kZy5wZGY=</p>
  <lm>20120821T170824Z</lm>
  <ce>1:1:4340ebcf79712dc5e3ef7d50bab98ba5:54687</ce>
</m>
		

Metadata Format v3

The following metadata format is used from version 2.5.1:

ArchiveDescription =

  <m>
    <v>3</v>
    <p>path</p>
    <lm>utc-lastmodified</lm>
    <ce>compressed_flag:encrypted_flag:original_file_hash</ce>
  </m>
 
where:
 
  path = base64(utf8(file name))
 
  utc-lastmodified = "yyyyMMdd\\THHmmss\\Z"
  
  compressed_flag - "1" if file compressed and "0" otherwise
  
  encrypted_flag - "1" if file encrypted and "0" otherwise
  
  original_file_hash - an md5 hash of uncompressed/unencrypted file
		

Example:

<m>
  <v>3</v>
  <p>Z2xhY2llci1kZy5wZGY=</p>
  <lm>20120821T170824Z</lm>
  <ce>1:1:4340ebcf79712dc5e3ef7d50bab98ba5</ce>
</m>
		

Metadata Format v2

The following metadata format was used from version 1.3.9:

ArchiveDescription =

  <m>
    <v>2</v>
    <p>path</p>
    <lm>utc-lastmodified</lm>
  </m>
 
where:
 
  path = base64(utf8(file name))
 
  utc-lastmodified = "yyyyMMdd\\THHmmss\\Z"
		

Example:

<m>
  <v>2</v>
  <p>Z2xhY2llci1kZy5wZGY=</p>
  <lm>20120821T170824Z</lm>
</m>
		

Metadata Format v1

The following metadata format was used in very first versions of FastGlacier:

ArchiveDescription =

  <ArchiveMetadata>
    <Path>path</Path>
    <LastModified>lastmodified</LastModified>
  </ArchiveMetadata>
 
where:
 
  path = base64(utf8(file name))
 
  lastmodified = rfc-822-date-time(file last write time)
		

Example:

<ArchiveMetadata>
  <Path>Z2xhY2llci1kZy5wZGY=</Path>
  <LastModified>Wed, 19 Sep 2012 11:11:11 +0000</LastModified>
</ArchiveMetadata>