If the MySQL /vastorage hard disk is formatted with the Ext-3 file system, inodes can be consumed until no more files can be added to the disk, even though space still exists.
Micro Focus recommends, therefore, that the innodb_buffer_pool parameter be set to 60% of total RAM allocated to the appliance.
To learn more about inodes and proper allocation based on the potential number of files that are created on the file system, see The File System in Reality, in the The Linux Documentation Project.