To modify vm.min_free_kbytes , complete the following steps: 

1. Check the total memory of the system by running the following command: 

#free -k 

2. Calculate 5-6% of the total memory in KB with a max of 2000000. 

3. Add vm.min_free_kbytes = <value from step 2>  to the /etc/sysctl.conf  file. 

4. Run sysctl -p /etc/sysctl.conf  to permanently set the value. 

## 8.8 Increasing the default maximum number of inodes in IBM Spectrum Scale 

The IBM Spectrum Scale default maximum number of inodes is fine for most configurations. However, for large systems that might have millions of files or more, the maximum number of inodes to set at file system creation time might need to be changed or increased after file system creation time. The maximum number of inodes must be larger than the expected sum of files and file system objects being managed by IBM Spectrum Archive EE (including the IBM Spectrum Archive EE metadata files if there is only one GPFS file system). 

Inodes are allocated when they are used. When a file is deleted, the inode is reused, but inodes are never deallocated. When setting the maximum number of inodes in a file system, there is an option to preallocate inodes. However, in most cases there is no need to preallocate inodes because by default inodes are allocated in sets as needed. 

If you do decide to preallocate inodes, be careful not to preallocate more inodes than will be used. Otherwise, the allocated inodes unnecessarily consume metadata space that cannot be reclaimed. 

Further considerations when managing inodes: 

1. For file systems that are supporting parallel file creates, as the total number of free inodes drops below 5% of the total number of inodes, there is the potential for slowdown in the file system access. Take this situation into consideration when creating or changing your file system. 

2. Excessively increasing the value for the maximum number of files might cause the allocation of too much disk space for control structures. 

To view the current number of used inodes, number of free inodes, and maximum number of inodes, run the following command: 

mmdf Device 

To set the maximum inode limit for the file system, run the following command: 

mmchfs Device --inode-limit MaxNumInodes[:NumInodesToPreallocate] 

