AkoZ on "[Plugin: WP Clone by WP Academy] mysql error stops bckp process"

tried 20000000 and it shows exactly the same message ( "Fatal error: Out of memory (allocated 28573696) (tried to allocate 4104 bytes) in SITE ADRESS/wp-admin/includes/class-wp-filesystem-base.php on line 312" )
tried 3000000 and same..
100000 same .. 100 000 000 idem..
but i've seen some message in bottom .. :
may be ?? :

Memory limit: 256M
Maximum execution time: 30 seconds
PHP version : 5.4.12
MySQL version : 5.1.67
Directory list:

Uploads path :
site adress//wp-content/uploads

Plugin path :
site adress/wp-content/plugins/wp-clone-by-wp-academy/

Plugin URL :
site adress/wp-content/plugins/wp-clone-by-wp-academy/

Backup path :
site adress/wp-content/uploads/wp-clone/

wp-content path :
site adress/wp-content

Site Root :
site adress/

ABSPATH :
site adress/

i think that comes from the host .. coz i've an other memory pb ..