Backup - Append vs Overwrite?

Hi,
If backing up a database to a disk file from within Enterprise Manager, it
seems you still get a choice between "Append" and "Overwrite". I don't
understand how these options work with disk files.
Does it mean that if you supply the exact same file name as an earlier
backup, the backup will be appended to the existing file (the file will
double in size but you'll still only have one file?).
Is it the case that if you supply a FileName that's never been used before,
it makes no difference whether you choose Append or Overwrite at this stage?
I've always used Maintenance plans for backup, and it seems you don't get a
choice about Append and Overwrite.
Thanks for any help.
Gerry Hickman
SSRU SysAdmin
See inline.....
>If backing up a database to a disk file from within Enterprise Manager, it
>seems you still get a choice between "Append" and "Overwrite". I don't
>understand how these options work with disk files.
>Does it mean that if you supply the exact same file name as an earlier
>backup, the backup will be appended to the existing file (the file will
>double in size but you'll still only have one file?).
Yes it appends the backup to the file so you have one file
and two different backups in the file.
>Is it the case that if you supply a FileName that's never been used before,
>it makes no difference whether you choose Append or Overwrite at this stage?
There is nothing to append to as it will be making a new
backup.

>I've always used Maintenance plans for backup, and it seems you don't get a
>choice about Append and Overwrite.
The sqlmaint utility which the database maintenace plan uses
always does an append. You could always just write your own
backup in T-SQL using the with init or noinit options which
controls the append or overwrite behaviors. See BOL Backup
for more details on the options.
-Sue