Hi, I have two bind mounts of the same filesystem
$ grep "/tmp" /etc/fstab /dev/vg0/tmpdirs /mnt/tmpdirs ext4 acl,user_xattr,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0 1 2 /mnt/tmpdirs/tmp /tmp none bind 0 0 /mnt/tmpdirs/var/tmp /var/tmp none bind 0 0 Using mv to move files between the bind mounts makes a slow copy: $ time mv /var/tmp/BIGFILE /tmp/ real 0m0.622s user 0m0.001s sys 0m0.621s In theory mv could know somehow that's the same filesystem and do it like this: $ time mv /mnt/tmpdirs/tmp/BIGFILE /mnt/tmpdirs/var/tmp/ real 0m0.004s user 0m0.001s sys 0m0.003s Would it be possible to optimize mv regarding bind mounts? Or perhaps are there other filesystems which do this better than ext4? Specially the case that the original whole filesystem (/mnt/tmpdirs) is umounted should work too somewhow. cu, Rudi
