Is there such a filesystem available? It seems like it wouldn't be too hard to implement... Basically do things on a block by block basis. Store md5 of a block in the table, and when writing a new block, check if the md5 already exists and then point the new block to the old block. Since md5 is not guaranteed unique, might need to do a diff between the 2 blocks and if the blocks are indeed different, handle it somehow. When modifying an existing block that has multiple pointers, copy the block and modify the new block. I know I'm oversimplifying things a lot, but something like this could work, no? Would be a great filesystem to store backups on, or things like vmware volumes... Russ Sent from my Verizon Wireless BlackBerry _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos