[Info-vax] fixing a saveset's attributes: attachment, not ftp

[abrsvc]

My understanding is that BACKUP uses different block sizes depending upon whether the saveset is created on tape or disk.  These blocks are used to create CRC blocks which can be used to re-create a block should one fail to be read.  This is one reason why savesets can be larger than the data being saved.  I am over simplifying this, but you get the idea.  e.g. Larger block sizes allows for more efficient data transfer, but may also allow for more data being lost should a few blocks be unreadable from the saveset medium. 

The size of the backup "block" is independent of any record attributes of the files being saved into the saveset.

Dan