Multiple backup sets with a single destination
This article only applies to CrashPlan software version 3 or newer, not to version 2010.
Backup sets can back up to separate destinations or to a single destination. However, if you back up multiple sets to a single destination, there are some important scenarios to consider. These considerations apply if you specify file exclusion rules, or if you specify unique version and deleted file retention preferences for the sets that share a destination.
CrashPlan application setups using the following features:
- Multiple backup sets and
- Unique version or deleted file retention settings or file exclusions and
- To a single destination (shared by different sets).
File exclusions specified for any backup set impact all sets backing up to the same destination.
Suppose set A and set B back up to destination 1. The sets have different file exclusion rules.
- Backup set A (below) is set to exclude files ending in .mp3, .mp4, and .wav
- Backup set B does not specify any exclusions
Even though exclusions are not specified for set B, MP3s, MP4s, and WAV files from this set will not back up to destination 1. Exclusions applied to a backup set are applied to every backup set backing up to the same destination.
Case study 1
A user would like to have two backup sets where:
- Backup set 1: File selection includes everything in her Documents folder. A file exclusion is used to exclude her PST file for Microsoft Outlook.
- Backup set 2: File selection includes only the folder containing Microsoft Outlook PST file. No file exclusions are indicated.
This scenario does not work if both sets back up to the same destination (e.g., cloud, an external hard drive). CrashPlan may back up the PST file from backup set 2 initially. However, when the file verification scan for backup set 1 runs for that destination, it sees the exception for PST files and removes the file from the backup archive.
Case study 2
- Backup set 1: File selection includes everything in her Documents folder. File exclusions are used to exclude AVI and MPEG files. The set backs up to both cloud destinations.
- Backup set 2: File selection includes everything in her Documents folder. No file exclusions are in place. The set backs up to an external hard drive.
This scenario works because she is using backup sets with different destinations. The AVI and MPEG files excluded from backing up to CrashPlan cloud, will back up successfully to the external hard drive destination.
Version and deleted file retention settings
Only one set of version and deleted file retention settings can be applied to backup sets backing up to a single destination:
- When multiple backup sets back up to a single destination, the version and deleted file retention settings from the backup set with the highest priority are applied to all sets backing up to that destination.
- If you would like different backup sets to have different version and deleted file retention settings, back up to multiple destinations.
Let's say you create two backup sets, both backing up to destination 1. The two sets have different version and deleted file retention settings:
- Backup set A (fig. 1) is set to remove deleted files every day
- Backup set B (fig. 2) is set to never remove deleted files
If backup set A is set as priority 1 (fig. 3), all deleted files, regardless of backup set, are removed from destination 1 after a day.
If you change the backup set priority so that backup set B is now the first priority, then deleted files are never removed from destination 1.
Case study 1
A user would like:
- A version of files in her Documents folder retained every hour for the last week and
- A version of a photo in her Photos folder retained every day for the last week
This scenario does not work if the user only backs up to one destination with these settings. Assuming that the Documents folder is the top priority, CrashPlan will keep one version of each file for every hour for the last week.
Case study 2
A user would like:
- A version of files backed up to all cloud destinations created every 15 minutes for the last week
- A version of files backed up to her external hard drive created every day for the last week
This scenario works because she is using backup sets with different destinations.