Hi David,

As this is an snapshot based backups you have to consider 4 things:

1.- Snapshot policy

2.- Group interval

3.- Roll-over to tape or persistent snapshot

4.- Schedule (basically check the "Force Incremental" option in the group).

Having this said first of all you need to know if you want that backup to be rolled over to tape or if you just want to have an snapshot in case of restore within the next backup rolled over to tape.

Lets say you want all backups to be rolled over to tape, but first a full and then incremental, then you can just set the "serverless backup" snapshot policy and check the option "Force Incremental" in the group. This option will run a backup but, if there has been a full backup within the interval specified in the group properties then the backup will be taken at incremental level instead of full.

You can also do it manually, by changing the level of the backup in the group properties (set level instead of schedule to incr.), but this is a bit annoying and could lead to issues in the backup administration.

If you just want the full backup to be rolled over to tape, then I would suggest to change the snapshot policy and forget about the levels, so that you can take snapshots every 3 hours but only the first one will be rolled over to tape, the others won't, so you save storage in the media. Anyway important thing to know about persistent snapshots is that:

1.- Only FULL level snapshots are supported, so if you tick the force incremental this will fail

2.- Because of the way VSS works, you will be able to keep only 2 snapshots not rolled over to tape. Let me explain it better:

- Full backup -> Tape

- Full persistent snapshot (1) -> stored locally on Exchange server (bear in mind also disk space requirements)

- Full persistent snapshot (2) -> stored locally on Exchange server

- Full persistent snapshot (3) -> stored locally on Exchange server. This will delete the snapshot (1)

- Full persistent snapshot (4) -> stored locally on Exchange server. This will delete the snapshot (2)

- Full persistent snapshot (5) -> stored locally on Exchange server. This will delete the snapshot (3)

And so forth

It's very important to have enough space if you go for the approach of keeping persistent snapshots, otherwise that could lead to a file system filled up, and some downtime in the Exchange server.

I hope that helps.

Thank you.

Carlos.

Hey David,

Did this work for you or do you need any further information?

Thank you.

Carlos.

Hello,

I don't have the time for the moment to apply this modification.

But i do some test and the results is not fine for me.

I would have hoped to have a simple solution

Like 1 job with a simple schedule Full Sunday and Incr/Diff the rest of week...

Play...

But as an habitude for Exchange to do more complicated when this can be simple...

Hi David,

You can have a simple schedule as you mentioned, Full weekend and incremental on weekdays, no problem at all, but the point is the interval of your backups. Do you require only one backup per day? If so you can set the serverless snapshot policy, set schedule to full weekend and incremental weekdays, and interval of 24:00 (one day).

If you set that schedule you should be fine.

Thank you.

Carlos.

True..

I have forgot this detail

I must do 8 backup by day.

One full and 7 incr or diff..

I try the "force incremental" it's works, but just one time..

It's possible to do the first backup of day a full backup and the next only incr or diff ?

Well, use the week schedule (Full-Inc Su) but on one day (Full-Inc 0:00)

Thank you.

Ok i understand the point 1 and 2, but i don't understand the last part.

When the first full run ?

If i check "force incremental" could set the interval to 3 ?

And the next day when start the Full ?

Hi David,

Yes you can, but these are the options:

1.- Bear in mind that only FULL snapshots are supported to take persistent snapshots, so all backups should be full if they are not rolled over to tape.

2.- You can set a snapshot policy to take 8 snapshots per day, all full, but only the first one is rolled over to tape.

3.- You could set serverless backup, check the "force incremental" and interval to 4, so you will have 6 snapshots per day. Backup will be started every 4 hours (6 times per day), and roll all of them to tape. That option should allow you to take incremental backups, however that will require more storage (tape or disk) to store the backups.

Let me know if this helps and if you need help in the configuration of the snapshot policy.

Thank you.

Carlos.

Ok,

In this configuration (your docx), the interval is 24:00, the snapshot will run every 3 hours because you set 8 snapshots in Nb of snapshot ?

And when the Full will run ?

And yes I would be looking for that one to be full, it's necessary or not ?

Ok i understand.

One thing again for my information.

How  VSS can do an incremental snapshot ??

Or NMM know is an exchange backup and do a snapshot only for log ?

Hi David,

That's actually a good question, but there is an explanation behind that:

VSS is "stupid" when it comes to perform snapshots, it's the requestor (in this case NMM) who defines what is going to be backed up, and the level.

When NetWorker instructs NMM to take an incremental, NMM knows that it has to backup only the logs, and this is the mechanism of backups in general, not only for NetWorker but for any backup software.

So having this said, VSS will take snapshot of the files (or writer if you prefer) to create the snapshot requested by NMM (Requestor).

By having the "Force incremental" option checked, NetWorker is telling to NMM to run an incremental backup=backup only logs=take snapshot only of the drives containing the logs.

Again, the snapshots are not incremental, is the requestor the one who indicates the files that have to be included in the snapshot. In this case Exchange writer is aware that only the logs have to be saved, so it will create only the snapshot for the logs, and not for the DB.

Hope that helps to clarify.

Thank you.

Carlos.

Ok.

I understand.

And i very happy finally is very simple.

Thanks a lot for your help.

David.

Hi David,

I'm glad this is clear now.

If you are curious about the levels and files of the snapshots, you can take a look at the xml files:

run:

nsrsnap_vss_save -G

This will create the xml files for each writer. Open the Exchange Writer.xml file and you will see the information of the writer about files etc.

Let us know how the backup works with the snapshot policy and interval definer.

Thank you.

Carlos.

Hi Carlos,

In my test infrastructure all works fine.

The full backup start at 00:30 and the next 7 backups are incremental, also many thanks again.

This infra have no many traffic and change in Exchange.

The volume of full backup of this infra is 7 Go, the backup time is average of 30 min.

The volume of incr backup is 120-130 Mo, the backup time is average of 30 min too.

Also, today i have make the modification on production infrastructure.

And i hope Networker will don't take as long to incremental as a full backup...

Regards

David

I don't understand my actualy problem.

My test on my test infrastructure was not really representative.

Because all DB were on same server and normaly they are balanced.

I have do the balancing between the 2 servers.

Also, my 2 groups are configured in "force Incremental", and start with no error.

Now, when i run the two groups in same time, one of two run a Full backup and the other an Incr...

But when i run one group after other, the second group run in incremental backup.

I don't understand.