Metadata is data about data. For example, when saving a file, your device automatically records information about when the file was created or modified. CrashPlan supports file metadata, such as file modification date, and embedded metadata on all platforms. Downloaded files will include supported metadata as described in this article.
Why is metadata important?
Metadata gives context to our files and lets us use them in a functional way. For instance, file extensions are a basic form of metadata that give files context. Without a file extension, your device can’t differentiate a text file from a photo. The file extension metadata tells your device what applications can open the file.
Supported metadata is included in your downloaded files. However, there are several considerations:
- CrashPlan app: Metadata cannot be included with your files via web restore. To preserve metadata, download from the CrashPlan app.
- Different operating system: If you download a file to a different operating system than the one where the file originated, the CrashPlan app may not be able to include metadata supported by the original operating system. For best results, download files on devices using the same operating system.
- Metadata included in separate files: Sometimes, metadata can be included in a separate file. This can result in confusion when you restore files and find there are more files restored than expected. For example, Alternate Data Streams metadata is supported on Windows NTFS systems, but when you restore a file containing this kind of metadata to a non-NTFS file system, the metadata is placed into separate files.
What metadata can I include?
CrashPlan supports restoring specific forms of metadata for each operating system listed below. Since different applications can create and store metadata in different ways, we can’t guarantee that every form of metadata can be included. However, we have tested the CrashPlan app for the types listed below.
Normally, metadata is stored within the file it is describing, but metadata can be created and stored in a number of ways. Some applications store metadata in a separate database file. One example is the metadata created by Lightroom. The CrashPlan app may have difficulty backing up the database file if it is in use, but if you choose to write the metadata to the file itself, the CrashPlan app will back it up regularly.
Restore to a non-HFS+ file system
When copying a file (and therefore restoring) to a non-HFS+ file system, any info not in the data file is stored in a “dot-underscore” file. For example, if you copy an HFS+ file named MyMug.jpg to a FAT 32 volume, there will be a file named ._MyMug.jpg in addition to the MyMug.jpg file in the same location.