Jérôme Poulin wrote: > On Sat, Sep 26, 2009 at 8:13 AM, Jeff Layton <[email protected]> wrote: > >> Good morning, >> >> I'm running IOzone on a NILFS2 partition and it's running alot >> slower that I had expected. I'm pretty sure it's because of the >> checkpoints. I can change the protection_period to something >> very small (or zero). Would that improve the performance? >> >> > The protection period only affects how the cleaner daemon will clean > the old checkpoints, if 0 I guess it will just clean them up as soon > as it can but it won't stop creating them. You could, just for > benchmark purpose, kill nilfs_cleanerd which will stop checkpoint > related activities. > It will only stop the clean up of checkpoints outside of policy - correct? So it won't stop them from being created but it will stop the cleaning process.
>> In addition, is there a way to turn off checkpointing? >> >> > The whole filesystem is based on those checkpoint, the fact that it is > a log filesystem makes it so all writes are made at the end of the > device, and when a write is complete, a checkpoint is made. > Understood. But for benchmarks like IOzone where you are creating files and most likely syncing, this will trigger a checkpoint. I haven't looked too much at IOzone but it might even be causing a sync after each record right, again forcing a checkpoint. So I was looking for some way to control how often checkpoints are created - something like the protection_period option for the GC. But I understand that the checkpoint is a part of the design of the file system. Thanks! Jeff _______________________________________________ users mailing list [email protected] https://www.nilfs.org/mailman/listinfo/users
