search for: _permanent_

...ions to mitigate the fragmentation effects. Alas, there is no way to do this purely at the filesystem level. From Dave Chinner, one of the lead XFS devs: "What you want is _physical_ preallocation, not speculative preallocation. i.e. look up XFS_IOC_RESVSP or FIEMAP so your application does _permanent_ preallocate past EOF. Alternatively, the filesystem will avoid the truncation on close() if the file has the APPEND attribute set and the application is writing via O_APPEND... The filesystem cannot do everything for you. Sometimes the application has to help...." How great would the effort...