Command RR[N] - add the data recovery record


Recovery record is the data area, optionally added to archive and containing error correction codes, namely Reed-Solomon codes for RAR 5.0 archive format. While it increases the archive size, it helps to recover archived files in case of disk failure or data loss of other kind, provided that damage is not too severe. Such recovery can be done with "r" repair command. ZIP archive format does not support the recovery record.

Optional 'N' parameter defines the recovery record size as a percent of archive size. If it is omitted, 3% is assumed. Maximum allowed recovery record size is 1000%. Larger recovery records are processed slower both when creating and repairing. Due to service data overhead, the actual resulting recovery record size only approximately matches the user defined percent and difference is larger for smaller archives.

In case of single continuous damage, typically it is possible to restore slightly less data than recovery record size. Recoverable data size can be lower for multiple damages.

If recovery record is partially broken, its remaining valid data still can be utilized to repair files. Repair command does not fix broken blocks in recovery record itself, only file data is corrected. After successful archive repair, you may need to create a new recovery record for rescued files.

While the recovery record improves chances to repair damaged archives, it does not guarantee the successful recovery. Consider combining the recovery record feature with making multiple archive copies to different media for important data.

This command is the command line equivalent of archive management command Protect archive from damage.

Examples

  1. add the data recovery record of default 3% size to archive backup

WinRAR rr backup

  1. add the data recovery record to archive pictures and set its size to 5% of total archive size

WinRAR rr5p pictures