I am also having the same issue, I am using Version psa v8.1.1_build81070423.15 os_FedoraCore 4
OS Linux 2.6.16-rc6-060427a
THis is the one of the error message i get when trying to do back up:
ERROR: PleskFatalException
Main class for type "backup" not define
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0: /usr/local/psa/admin/plib/common_func.php3:151
psaerror(string 'Main class for type "backup" not define')
1: /usr/local/psa/admin/plib/PMM/MigrationManagerFactory.php:101
MigrationManagerFactory->factory()
2: /usr/local/psa/admin/htdocs/backup/main_domain.php:23
AND
Runtime error: Unable to write to output file: No space left on device at /usr/local/psa/PMM/agents/shared/Storage/Splitter.pm line 84.
In my case I am also experiencing problems creating and deleting new domains.
This is the error message:
Error: Unable to update hosting preferences: system user update is failed: Unable to create system user: usermng: PAM password change failed: 20, Authentication token manipulation error
System error 111: Connection refused
AND
Domains >
ERROR: PleskException Create ShortcutCreate ShortcutUp LevelUp Level
dnsmng::update() failed: dnsmng failed: dnsmng: Unable to search PTR records for cheapsportstix.com :Got error 28 from storage engine
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0: /usr/local/psa/admin/plib/dns/DNSManager.php:792
DNSManager::updateDNSZone(object of type DNSZone)
1: /usr/local/psa/admin/plib/class.PhDomain.php:713
PhDomain->restartServices()
2: /usr/local/psa/admin/plib/class.PhDomain.php:616
PhDomain->update()
3: /usr/local/psa/admin/plib/class.BsDomain.php:369
BsDomain->update()
4: /usr/local/psa/admin/htdocs/domains/create_domain.php:149
Any help will be greatly appreciated.