The file system maintains a history of file system checkpoints known as Dynamic Superblocks. If the end user requires fast reclamation of free space after data deletions, the DSB count could be reduced to 2 for file systems <10TiB and 16 for file systems >10TiB. The default number of DSBs is 128. You can specify the setting at format time or change it at a later time by issuing the following command:
fs-set-dsb-count <file system> <dsb count>
Example:
To change the DSB count of "fs1" to two DSBs:
fs-set-dsb-count fs1 2
Note that changing the number of DSBs requires that the file system be unmounted.