I'm trying to back up 66 gigabytes to a NAS by making a tarball, but "tar -cSf ..." quits with a "memory exhausted" error after gigabyte 62. My Linux machine has a gigabyte of RAM and a gigabyte of swap space.
(edit) I tried it again about where tar gave up and tar quickly gave up again, so it looks like it may be having trouble dealing with a special file.
This data is surprisingly resistant to being backed up. rsync is 4 times slower than tar because the NAS isn't very fast and it quits in the middle with 'connection reset by peer'; 'cp' doesn't work well on the cifs share because it can't create the special files. Is there a better way?