Ok - I'm assuming your running Arcserve2000?
Slot 7 can be designated as a cleaning slot in device setup, so that can be forgotten about (?)
I would recommend that you set a new job up as a rotation one, and use a media pool - let Arcserve sort out the slots.
Go to the media pools screen, and create a new pool - call it something appropriate like "weekly". Leave the serial number parameters as they are, and set Min number to 9, and retention time to 13 days (you may have to play around with this a bit, but that's a good place to start - you'll be able to see if media is being put back into scratch too soon by examining the pool contents). If you've got any spare tapes to populate the pool with, that'd be better than using your current tapes. If you're unsure, you'll need to inventory the new tapes in device manager, label them (call them anything you like), but assign them to the new pool. Make a note of the serial numbers it assigns them, and physically put a label on them yourself. You should then see them in the scratch set section of the media pool you created.
Start a new backup job, and make the selections that you want backing up.
In the destination, point it to the "*" as before.
Under the schedule tab, select "use rotation scheme", and then select "5-Day weekly differential backup, full backup on Friday"
I don't recommend this until Friday, as even though you've set it as differential, Arcserve thinks it knows better and will always make the first ever run a "full".
When it runs, it will automatically relabel the tape as "Monday" or whatever day it is. It won't attempt to over-write the previous Monday tape as that will still be in the save set and therefore protected. You may need to go slightly higher than just 10 tapes in the pool, to have a few available in the scratch set. After the backup, if you examine the device manager, you can see which tape (in which slot) has been used, and remove it from the autoloader if you want to.
The Monthly
This one's a bit more tricky & I've had to think about this! There's a certain amount of manual intervention involved I'm afraid. Create a new pool, and call it temp. Get 12 tapes, format them with a serial number and assign them to this temp pool. Then delete the pool. Physically label the tapes as before. Unfortunately, this is the only way to get them labelled with a serial number which makes for easier admin. Assuming you would run it on the last Sunday of every month. Set the job destination as before (*), under schedule, use a custom schedule, repeat method is ""Weeks of month", select the "last" check box, and then "Sunday" as the Day of Week. When you are ready to run the job, always erase the target tape that will be used, erase it using the device manager (Quick erase - media label only). Then in the options for the job, change the "Options for first media" to "Overwrite same media name or Blank media" - thus it will have to pick up the tape you've just erased (it's blank), and all of the other tapes that may be in the loader are in a separate media pool and thus protected.
If any of this doesn't make sense, let me know (Mark@AGSolutions.co.uk) and I'll try & clear it up.
Regards
Mark