On Sep 13, 2010, at 10:54 AM, Orvar Korvar wrote: > To summarize, > > A) resilver does not defrag. > > B) zfs send receive to a new zpool means it will be defragged
Define "fragmentation"? If you follow the wikipedia definition of "defragmentation" then the answer is no, zfs send/receive does not change the location of files. Why? Because zfs sends objects, not files. The objects can be allocated in a (more) contiguous form on the receiving side, or maybe not, depending on the configuration and use of the receiving side. A file may be wholly contained in an object, or not, depending on how it was created. For example, if a file is less than 128KB (by default) and is created at one time, then it will be wholly contained in one object. By contrast, UFS has an 8KB max block size will use up to 16 different blocks to store the same file. These blocks may or may not be contiguous in UFS. http://en.wikipedia.org/wiki/Defragmentation > Correctly understood? Clear as mud. I suggest deprecating the use of the term "defragmentation." -- richard -- OpenStorage Summit, October 25-27, Palo Alto, CA http://nexenta-summit2010.eventbrite.com Richard Elling rich...@nexenta.com +1-760-896-4422 Enterprise class storage for everyone www.nexenta.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
