Migrating to a new Library Scenario

[AbdulAzeez_Al_D]

Good day,

We have been using an LTO 1 stand alone drive and have recently upgraded to a 24 slot library with an LTO 3 drive.

We used to swap tapes on a daily basis for the end of day backups and now we need a way for setting up media usage for the library.

How can we do this apropriately ? Multiple part questions follow - you have been informed !

Given the following scenario:

• Daily Backups to include: Exchange 2003 full Mailboxes & store backup, SQL 2000 Databases and users folders.
• Currenlty have 2 jobs for the daily backup selection above (1 for SQL and folders and the other for Exchange)
• We have 3 media sets set up as (Daily, Weekly and Monthly) Each with append & overwrite settings.
• We require that each weekly tape be available with 2 weeks worth of backups on it before it is overwritten.
• We will be using 2 sets of daily tapes for each month
• Each LTO 1 tape can hold 100GB on it and the size of our backups in GB currently are as follows:
• Daily Exchange backup - 28 GB
• Daily SQL & Folders backup - 2.5 GB

Question 1 -How can we manage media in the library as we used to have 4 tapes labeled Saturday - Tuesday for the working days and Wednesday for the end of week full backups? Do we need to partition the library and target the daily jobs to a set of tapes rather than our individual labeled daily tapes ?

Question 1 b - Would it be better to create new media sets based on data type and target the backup to the media set based on data i.e Exchange media set, SQL Media set. And also Segregate the jobs based on type?

Question 2- Would the append period be 7 days and overwrite period - 13 Days ? To make the same tape available for overwrite on the 4th saturday of the month.

Wheew...

[Robert_Schmidt_]

Hi

You said "Each LTO 1 tape can hold 100GB on it ..."

You do know that LTO3 can NOT write to LTO1? - only read.

So, you have to buy some new media. Your data will easily fit on LTO2 (LTO3 drive can write to LTO2), but if you have to get new media, I would suggest you spend the few extra $$ to get LTO3 and future proof yourself a little.

Now, as for how to do it. Please tell me realistically how many LTO3 your business can afford, and I could think about your comments and suggest a way to do it. This is the sort of cycle I work with on a PowerVault 132T with LTO3 drive - but, I have the luxury of as many data cartridriges as I want.

Another question - when you say each LTO 2 can hold 100Gb - are you or your manager opposed to using hardware compression? - could affect how you could get by with less cartridges.

Cheers

[AbdulAzeez_Al_D]

Given the Data size that we have to backup everyday and the end of month full backups, we would be going with LTO 2 - 400GB tapes.

For the compression I am merely getting 1:1.31 on each media.

The dilemma we are facing is how to shift from daily tapes to partitioning the library, apend / overwrite setting are clear.

With the LTO 2 we can go for the full month with one set of daily and still have room form more given the current and expected data size expansion.

[AbdulAzeez_Al_D]

Using the new LTO 2 Tapes - 400GB and given expected data size growth and after discussing this with the team

Our Suggested append / overwrite for each media set could be as follows:

                                                              Append          Overwrite Protect

Daily Media Set (4 Tapes in the set) :    5 Weeks             6 Days

Weekly Media Set (4 Tapes in the Set)  4 Months           27 Days

Monthly Media Set (12 tapes for each month) 1 day        2 years

The monthly is kept offline for 2 years, however what would the suggested Archival of company data be after the 2 years, keeping in mind that each tape would still have plenty of room for appending. Recycle the media or other. Whats the norm out there ?

[AbdulAzeez_Al_D]

We will be using LTO 3 tapes (4 for Daily) (4 for the Weekly) for - Daily and Weekly Backup tapes
LTO 2 tapes for Monthly backups which are kept offline.

[Robert_Schmidt_]

Hi

back in your first post, you said you were going to use "2 sets of daily tapes for each month".

So, to make sure your data isn't overwritten if the wrong tape is in, your "daily media set" overwrite should be 13 days instead of 6.

If I understand you correctly, the first job of any backup (daily, weekly) is going to overwrite the tape, so the append settings aren't so important.

As for partitioning...

Set up a partition of 4 slots for your daily tapes. Target your 'daily' job to that partition. At the start of your work 'week', you can load all 4 daily tapes for that week. Once you have been through a whole cycle of tapes, only the tape for that day will be available for overwrite (in the media set). Good practice would say you remove the tape for a specific day once the backup is completed and remove it from the computer room to another 'location'.

Your 'weekly' job and your 'monthly' job are never going to run at the same time - and because your amount of data is low, you are not going to use more than one LTO. So, make a one-slot partition and use it as the target for both the 'weekly' and 'monthly' jobs.

[AbdulAzeez_Al_D]

Yes In the first post I did indicate using 2 sets, however given the increased capacity using LTO 3 we decided to keep it to 1 set for the daily which is 4 tapes Saturday - Tuesday.

Hence the 6 Days Overwrite protect as the tape will be recycled after Appending for 5 weeks.

the first job of any backup will overwrite the tape as we are starting with new tapes. Once things roll after the first backup for each tape the append and overwrite periods should kick in and the cycle would commence. After the first job each tape should overwrite on the same day of the first backup on the sixth week.

The partitioning part looks reasonable however,

I still need to clear this confusion:

The partition will include the 4 slots for the daily tapes for the daily media set. Once the Saturday backup job completes the append / overwrite period for the tape starts. Backexec should be using a new tape the next day and so on until the last day of the work week (Tuesday).

Now on the next Saturday will backexec be using the same Saturday tape that was used or any of the tapes?

[Robert_Schmidt_]

Do I understand correctly ...

You will now have 1 set of daily tapes (Sat, Sun, Mon, Tue).

 - AND, you intend to use these 4 or 5 times (depending on the month) - starting with an overwrite the first time in the month and append for each of the subsequent occurances of that date.

Then, the first use of that day in the next month, you will overwrite again.

Hmmm. You have not expressed any $$ problem with acquiring tapes. So, why worry about "making best use" of all the storage on the tape? - it actually complicates your backup jobs (overwrite vs. append) AND exposes you to some risk. Here's how: say, for example, on the third Sat. of the month the drive "eats" your tape - or someone drops and smashses it, or ... - you have lost your backups from the 1st and 2nd Sat. - maybe that doesn't matter in your particular business, but maybe it does - only you can decide.

Plus, it makes your overwrite/append rules more confusing for your substitute people. If you have 4 or 5 sets of daily tapes, the job is always overwrite, the overwrite protection is 28 days, append doesn't matter, AND you can get a daily tape out of your loader once it's used and store it "away" for the entire month.  - Plus, if you're using and off-site storage company, it makes your tape movement a lot simpler. AND, further, is someone puts in the wrong tape, because EVERY job is overwrite the media rules will make sure the job isn't appended (with the possibility of running out of space) and the rules will also make sure the tape isn't overwritten.

What do you think?

[AbdulAzeez_Al_D]

Yes you're right on the requirements we have in mind,

and true more tapes with an overwrite every 28 days will provide you with more room for recovery.

However taking tapes out on a daily basis beats our purpose in investing in a 24 slot library. Keeping in mind we will also run parallel jobs for backup to disk daily, weekly etc.. We do have a small team handling the backup and other tasks in the dept. (2 Staff). So we are most likely to leave tapes till end of week (Wednesday) when the only tape removed is the weekly/monthly. Daily's to stay. - your point on possibility of disaster is well taken.

We wish to use the LTO 3 daily tapes to append for 6 weeks before overwriting the daily tape on the same day occurance.

to illustrate (Append 6 Weeks, Overwrite protect 6 days) the same for each of the daily tapes whoch are apended to on thier respective day.

Week 1

SAT Tape(Append)

Week 2

SAT Tape(Append)

Week 3

SAT Tape(Append)

Week 4

SAT Tape(Append)

Week 5

SAT Tape(Append)

Week 6

SAT Tape(Append)

Week 7

SAT Tape(Overwrite)

If this setup doesn't serve well, in our intended requirements how can we tailor this strategy given the 4 daily tapes that remain in the library ?

Maybe just target the daily backups to the daily media set and forget about arranging the backups to specified days of the week