GlusterFS tuning

Here, the main variable is performance.cache-size. This setting specifies the amount of RAM to be allocated as a read cache for the GlusterFS volume. By default, it is set to 32 MB, which is fairly low. Given that the selected VM has enough RAM, this can be bumped to 4 GB using the following command:

gluster volume set gvol1 performance.cache-size 4GB

Another essential parameter once the cluster starts growing is performance.io-thread-count. This controls how many I/O threads are spawned by the volume. The default is 16 threads, which are enough for small-to-medium clusters. However, once the cluster size starts growing, this can be doubled. To change the setting, use the following command:

gluster volume set gvol1 performance.io-thread-count 16

This setting should be tested to check whether increasing the count improves the performance or not.