Question about tape rotation strategies

[Marc Krawitz]

I was thinking of using the grandfather-father-son approach which uses 12 tapes - 4 daily, 5 weekly, and 3 monthly.  What approaches are other people taking?  What does the VA do?

 

Thanks,

 

Marc

 

 

[kdt...@gmail.com]

Can you educate me more about this?

Kevin

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> <div>I was thinking of using the grandfather-father-son approach which uses 12 tapes - 4 daily, 5 weekly, and 3 monthly.&nbsp; What approaches are other people taking?&nbsp; What does the VA do?</div>
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> <div>Thanks,</div>
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> <div>Marc</div>
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[Chris Richardson]

Kevin;

This is a means of keeping at least two good backups by sacrificing the
oldest (the grandfather) for the next backup, the son. Should the new son
not create properly, then the old son and the old father, are still there.
When the backup is done, there is a new son, new father, and the new
grandfather (now the oldest good backup) are available to recover from.

We actually do a 28 day backup, two tapes a night. and then rotate through
the same tapes again. That gives us 4 weeks of backups top draw from.

[Rodney H. Kay]

The VA (the last I knew) used enough tapes for a two week rotation. Tapes
are stored off-site for two weeks and then re-used. Personally, on my own
system, I use enough tapes for a one week rotation.

Rodney

-----Original Message-----
From: Hard...@googlegroups.com [mailto:Hard...@googlegroups.com] On Behalf
Of kdt...@gmail.com
Sent: Tuesday, August 22, 2006 4:13 PM
To: Hardhats
Subject: [Hardhats] Re: Question about tape rotation strategies

[Chris Richardson]

We do off-site also, but we are primarily a development site and we keep our
backups bit longer than customary.

[mkra...@gmail.com]

>From the web:

One of the most commonly used tape rotation schemes is called
Grandfather-Father-Son. This scheme uses three sets of tapes for daily,
weekly and monthly backup sets. To execute the Grandfather-Father-Son
rotation scheme, you will need twelve sets of media. The actual number
tapes required in each media set will vary depending on how much data
you need to backup.

The first set, "Son," represents your daily backups. Assign four tapes
as incremental daily backups and label them "Monday" through
"Thursday." These tapes will be used to perform daily incremental
backups and can be reused weekly on the day that they are labeled.

A second set of up to five weekly tapes, called "Father," is used to
perform full backups on the day in which you do not perform a daily
incremental backup. This media set should be labeled "Week 1" through
"Week 5" and can be reused monthly on the day matching its label.

The final set of three tapes, called "Grandfather," is used to perform
full backups on the last business day of each month and can be reused
quarterly.

This rotation scheme will back up data on a daily, weekly, monthly, and
quarterly basis. In some instances, archived data is required for
periods longer than one quarter. In these cases, media sets are often
pulled from the rotation and store off-site.

[Kevin Toppenberg]

We do a complete daily backup, with 5 tapes. One for each day. I the
scheme outlined here with montly and weekly backups added in for those
times when a complete backup can't be fit onto one tape? What is the
point of the monthly backup?

Kevin

[mkra...@gmail.com]

The point of the weekly and monthly backups is that data loss may not
be immediately apparent. In other words, lets say hypothetically that
three weeks ago, five of your patients' records were deleted. You may
not become aware of this situation for another two weeks. If you kept
only five tapes, that data would be gone forever.

Of course, recovery would be another story...

--Marc

[Mike Lieman]

Get a device and i/o which supports daily full backups.
Get a few boxes of tapes.

Week #1
-------------
Saturday-A
Sunday-A
Monday-A
Tuesday-A
Wednesday-A
Thursday-A
Friday-1

Week #2
--------------
Sat-B
Sun-B
Mon-B
Tues-B
Wed-B
Thu-B
Friday-2

Week #3
--------------
SatA - ThuA
Friday-3

Week#4
-------------
SatB - ThuB
Friday-4

PULL any END OF MONTH tapes from rotation, label them
MONTH-END-JULY-06, and replace with a fresh blank.

Lather, Rinse, Repeat.

You have 2 FULL WEEKS of full backups.
4 Weeks of Full Weekly Backups.
And a perpetual archive of month-end tapes.

Lather, Rinse, Repeat.