>>>Computing the space needed when moving files is similar, except that the blocksize of the target drive needs to be used in the calculation (you still use the number of bytes in use in actual use for each file; the slack space changes as the blocksize changes.)
>>>
>>>Ed
>>
>>If the problem is to figure out available disk space then DISKSPACE() should be used.
>
>Gives a ceiling value; compression makes life tougher in this case. Also, DISKSPACE uses a drive letter, not UNCs, as I recall.
>
>Ed

Checking available space is precaution measure and few more MB will not hurt. IMHO, this horse (thread) is dead:).