In previous releases the number of parallel fsck thread that could be active during recovery was set to 4. If a node failed over 12 file systems, log replay for the 12 file systems will not complete at the same time. The maximum parallelism was restricted to 4. The number was set to 4 since parallel replay of a large number of file systems would put memory pressure on smaller systems with less memory. However, on larger systems the restriction of 4 parallel processes replaying is not necessary. In this release this value is either dependent on the number of CPUs in the system, but you can get the value within given limits.