Error:
ORA-27090: Unable to reserve kernel resources for asynchronous disk I/O

create table test nologging parallel(degree 10) as select /*+ parallel (e 10) */  * from employees e ;
*
ERROR at line 1:
ORA-12801: error signaled in parallel query server P00R, instance
ORA-27090: Unable to reserve kernel resources for asynchronous disk I/O 

Solution:

1. Check the value of aio-max-nr parameter.

/sbin/sysctl -a | grep aio-max-nr

2. Following value is recommended in Oracle docs as shown below, First set the following value if it not fixed then increase the value.

fs.aio-max-nr = 1048576
https://docs.oracle.com/en/database/oracle/oracle-database/12.2/cwlin/changing-kernel-parameter-values.html#GUID-FB0CC366-61C9-4AA2-9BE7-233EB6810A31

3. If its not fixed then tried with increased the value as per note id: 748607.1

Edit the file /etc/sysctl.conf
fs.aio-max-nr= 3145728

4. Activate the changed value by running the following command:

sysctl -p /etc/sysctl.conf