qmail, qmail configuration and qmail queue reside in the /usr/local/qmail directory.
qmail recovery requires an additional step: some files in the qmail queue have special names that must match the inode numbers of these files. If you use the usual backup tools, the inode numbers are not saved. In order to fix the names of such files the following script must be executed after the /usr/local/qmail directory is restored from the backup:
/usr/local/qmail/bin/fix_qmail_queue.sh
This script is included in the Operations qmail service package and must be present on all Operations qmail service nodes.
Note: If a clustered qmail solution is deployed, the /usr/local/qmail/shared directory is an NFS mount point. This directory should be backed up and restored on a NFS server and excluded from backup on the clustered qmail service nodes.