chouinar@centrcn.umontreal.ca (Luc Chouinard) (11/09/90)
AFS distributed file system could be an answer. The AFS file system developped by the Trantor corporation is really user-friendly from an administrators point of view. AFS volumes (filesets): The volume or fileset unit in the AFS file system comprises a collection of files and directories, and forms a connected subtree. Those volumes can be glued together at mount points to make up the AFS tree. They can be viewed as standard UNIX file systems on one disk partition (or multiple partitions on IRIX). - Like IRIX 3.3.1 logical volumes, they can grow. But they can also shrink and they do it dynamically in respect to a per volume quota. - They can be moved from partition to partition and from server to server without the users being aware of the move. - And (To answer the original question) they can be be cloned. When a volume is cloned a backup volume is created which exists alonside of the original read-write volume on the same partition. At creation time the backup volume takes practocally no space. It will grow when aver a file is modified or deleted because a copy of the file will now be effectively part of the bakcup volume. Normally backup volumes are mounted on a mount point at the top of the original volume (typically .OLD). Usually backups volumes are cloned in the morning so users can undeleted files all day long with a simple command that looks in the .OLD subtree and moves the file from the backup to the original volume. (excuse my english...) +---------------------------------------------------------+ | Luc Chouinard Services Informatiques | | Administrateur de systeme Universite de Montreal | +---------------------------------------------------------+ | email : chouinard@CENTRCN.UMontreal.CA | +---------------------------------------------------------+