Barry, i just did a test about that. if you add another subvolume to the DHT volume and add new files into an existing directory they will be distributed over all DHT-subvolumes. I assume that the distribution on old subvolumes will stop when the free-space threshold is reached, but i did not test that. Moritz Am 21.07.2009 um 18:57 schrieb Barry Jaspan: > I have a question about this paragraph from the "Understanding DHT > Translator": > > "Currently hash works based on directory level distribution. i.e, a > given file's parent directory will have information of how the hash > numbers are mapped to subvolumes. So, adding new node doesn't > disturb any current setup as the files/dirs present already have its > information preserved. Whatever new directory gets created, will > start considering new volume for scheduling files." > > The last sentence suggests that if I have a single directory on a > DHT volume and it is getting full, adding additional subvolumes to > the DHT volume will not help because all the files in a directory > will only ever live in subvolumes that existed at the time the > directory is created. Is that true? > > Also, it sounds like an entry mapping each filename (hash number) to > a subvolume is stored in the extended attributes of the parent > directory for that file. What is the practical limit for the number > of files that can be stored in a single directory under this > system? It seems like eventually doing a lookup in the directory's > attributes would itself become a very expensive operation. > > Thanks, > Barry > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://zresearch.com/cgi-bin/mailman/listinfo/gluster-users
