FTP backup is created incorrectly if several APS use the same database: boost::filesystem::file_size: No such file or directory

Applicable to:

#PPPM-9656 "A database shared between instances of an APS application is backed up several times (as PPP-39525)"
Fixed in:
- Plesk Obsidian Release Candidate 1.0 04 June 2019

Please consider updating your server:

Full backups are set to be stored on FTP storage in Plesk > Tools & Settings > Backup Manager;
There are backups in local storage in Plesk > Tools & Settings > Backup Manager;
There are backup files left in /var/www/psa/dumps/clients;
The following error can be found in/usr/local/psa/PMM/logs/backup-<datetime>/backup.log:

CONFIG_TEXT: INFO: boost::filesystem::file_size: No such file or directory: "/usr/local/psa/PMM/tmp/pmm-de-tmp-repo-6TJGee/clients/exaple.com/domains/example.com/databases/example/backup-pv22s37_1811151802.tgz"
[2018-11-15 22:00:37.381|29034] INFO: pmm-ras finished. Exit code: 1

This is a Plesk bug PPPM-9656 that will be fixed in future product updates.

For workaround implement the custom fix:

Log in via SSH;
Backup /usr/local/psa/PMM/agents/shared/Storage/Storage.pm file:

# cp /usr/local/psa/PMM/agents/shared/Storage/Storage.pm{,.bkp}
Download the custom fix and unpack it to /usr/local/psa/PMM/agents/shared/Storage/ directory:

# wget https://support.plesk.com/hc/en-us/article_attachments/360019382613/Storage-PP-17.5.tgz
# tar -xzf ./Storage-PP-17.5.tgz -C /usr/local/psa/PMM/agents/shared/Storage/