On Tue, Nov 16, 2010 at 04:56:00PM -0500, Ivan.Novick@xxxxxxx wrote: > Hello, > > I am using the allocsize mount option to reduce fragmentation, by > ensuring extents are of a minimum size. > > Under a workload with heavy concurrency we noticed that disk space > usage went up noticeably. Expected behaviour. > Can someone clarify the expected behavior of allocsize. Does it > force files to be at least the allocsize size on disk, or is the > allocsize size reserved for each open file and then freed up if it > is not used and the file is closed, or does it work some other > way. The latter - it's an in-memory, per-inode speculative allocation that is removed when the file is closed. > For example if allocsize=1g and I open 1000 files and start > writing a small amount of data to each file â. Would the device > show as using 1000* 1g of disk space while the files are opened > and after they are closed then only the amount of space actually > written by the user would be shown as used on disk? Yes, exactly. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
