>On Wed, 2005-05-04 at 12:36, T. Horsnell wrote: > >> I'm trying to investigate tar speeds over NFS. I normally test >> tar speeds by 'tar cf /dev/null somefilesystem' but if the filesystem >> is an NFS one, using /dev/null as the output file is resulting in >> impossible tar speeds. If the tar output is directed to a file >> rather than to /dev/null, all is well. Does tar do some sort >> of magic if its tarring NFS stuff to /dev/null? For example: > >GNU tar recognizes /dev/null as something magic whether or not >the files are on NFS and it skips reading the actual data. This >feature is used by the amanda backup program to quickly obtain >estimates of full vs. incremental backup sizes. If you want >to force the files to be read, try 'tar cf - somedir >/dev/null' >instead. Aha. Many thanks! T. > >-- > Les Mikesell > les@xxxxxxxxxxxxxxxx > > >-- >fedora-list mailing list >fedora-list@xxxxxxxxxx >To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list >
