Troubleshooting open_files_limit in MariaDB

Troubleshooting open_files_limit in MariaDB

It may happen in the MariaDB logs that you see failures to set open_files_limit:

160318 21:48:04 [Warning] option 'open_files_limit': unsigned value 18446744073709551615 adjusted to 4294967295
160318 21:48:04 [Warning] option 'open_files_limit': unsigned value 18446744073709551615 adjusted to 4294967295
160318 21:48:04 [Warning] Could not increase number of max_open_files to more than 1024 (request: 4907)

Meaning MariaDB was unable to raise the limit of maximum file descriptors at startup, with all the subsequent problems it can cause. Sometimes it is simply due to a bad setting in configuration files, such as:

open_files_limit=-1