Tape recycle

The Tape Recycle field tells Auto Pilot how many daily, weekly, and monthly tapes to save before reusing any of them. Following is a description of each type of tape:

Daily - used for your daily backups (for example, you perform Differential backups Monday through Thursday)
Weekly - used for the last full backup of the week
Monthly - used for the last full backup of each month

If you picture each type of tape stored in its appropriate 'bin', then it becomes easier to understand how Auto Pilot reuses tapes. Consider the default Auto Pilot setup where you are doing a full backup every day and "preserving" 4 daily tapes, 5 weekly tapes, and 12 monthly tapes:

You would use the daily tapes (from the daily bin) on Monday, Tuesday, Wednesday, and Thursday. On Friday, which is the last full backup of the week, you would use a tape from the weekly bin. On the last full backup of the month, regardless of what day it falls on, you would use a tape from the Monthly bin.

Match the number of daily backups you perform per week to the number of daily tapes to save

When setting up your Auto Pilot set, keep in mind how many daily backups are being performed each week. Consider the default Auto Pilot set, where four is the number of daily tapes to preserve before rotation. This is because on Monday through Thursday, a daily backup is being performed. On Friday, the weekly backup is performed. The next Monday, you want to start over again, reusing the previous week's daily tapes. If you changed the scheme so that you were performing backups only on Tuesday and Thursday, with a weekly backup on Friday, then you should change the daily tapes to preserve to be two.

The minimum number of daily tapes required per week is the number of daily backups you are performing:

The number of daily tapes to preserve should match the number of daily backups you perform per week. You can enter a value of up to 250 for daily tapes to preserve.

Keep your weekly backups for at least a month before reusing them

The default setup for weekly backups is five. Some months, depending on your Auto Pilot setup, you will have five weekly backups performed before the monthly backup takes place. You don't want to start recycling your weekly backups before a monthly backup occurs. The range of valid values for preserving weekly tapes is 2-52.

The default setup for monthly backups is twelve. Monthly backups are considered the only form of 'permanent' backup, so in general, you want to take these off-site for storage, and don't want to recycle these tapes. The range of valid values for preserving monthly tapes is 0-12. If you don't want to use Auto Pilot's grooming feature, then you can set the number of monthly tapes to preserve to be 0.

The last full backup of the week is the weekly backup. The last full backup of the month is the monthly backup. You will always take the daily tapes from the daily bin, the weekly tapes from the weekly bin, and the monthly tapes from the monthly bin.

When does Auto Pilot re-use the tapes?

Auto Pilot will start re-using tapes after making the number of backups that you specified in the Tape Recycle fields. For the default setup, Auto Pilot will need to make 4 daily backups before it can start re-using the daily tapes, 5 weekly backups before it can start re-using weekly tapes, and 12 monthly backups before it can start re-using monthly tapes. When you first start Auto Pilot, you will need a blank daily tape for Monday through Thursday's backup. On the following Monday, Auto Pilot will start recycling the daily tapes by using the oldest one (last Monday's) first.

Earlier, Jim set up an AutoPilot set, called ENGINEER, to back up his UNIX hosts. Assuming his first backup is on March 7, 1994, after the first week his bins would look like the following:

On Monday, March 14, 1994, Auto Pilot would re-use the tape named F-ENGINEER-MON-3/7/94. (This tape was named with an 'F' instead of 'D' because the first backup of an Auto Pilot set is always a full backup, regardless of the type of backup method selected.)

On Monday, March 28, 1994, Jim's bins would look like this:

Auto Pilot always recycles the oldest tape first. It gets this information from ARCserve's database. You can always determine which tape Auto Pilot needs next by looking in the Auto Pilot Daily Log, under the Reports Manager.

Grooming and monthly tapes

If you are using Auto Pilot's grooming feature, SCO ARCserve/Open will not recycle monthly tapes, since any files that have been groomed would be gone forever if the monthly tapes were reused.