I use "vxdump 0bfu 63 /dev/rmt/0cbn" to dump files on to LTO 2 tape,
but when I use "vxrestore -ivf /dev/rmt/0cbn" to restore, the restore speed
is very slow. 2G database files, takes one and a half hour.
Could some one tell the problem? is it related to block size? if it is, what
block size need to be?

Thanks,