Monthly backups to Disk (NAS) - how to set up?

[FRuk]

Hi,

I am new to Backup Exec and am setting up a backup for a small client with relatively large volumes of data, approx 7TB. They are storing this data on a NAS and they have installed a second, larger NAS to hold backups of the production NAS and a couple of servers including Exchange. The backup NAS is about 11TB.

What I would like to do is to keep a rolling backup for 4 weeks - the client understands and accepts the inherent risk in only keeping data for this short period. What I *think* need to do is a Monthly Full, followed by a daily incremental, however I am not clear if this will work - the next Monthly Full would have to overwrite the existing Full, so would the incrementals taken before the new Full continue to be valid? Since I have overwritten the Full that they were staged from.

In order to do this, do I need enough space on the backup NAS to hold two Monthly Full backups? I have outlined my setup below, any suggestions or clarification would be very gratefully received - I am really picking this up as I go and I don't want to find in 6 months that I didn't get it right and can't restore some key files..

I have created 4 folders on the NAS;

Server/Exchange Backup Full
Server/Exchange Backup Incr
NAS Backup Full
NAS backup Incr

Which are added as Backup-to-Disk Devices in BackupExec

And created 4 jobs within Backup Exec;

Server/Exchange Backup Full
Server/Exchange Backup Incr
NAS Backup Full
NAS backup Incr

The full jobs go to the Full folders and the Incremental jobs to the Incr folders - I think perhaps this is wrong, and that the Full and Incremental jobs should go to the same folders.

Full jobs are currently set to Keep Data for 4 weeks and then overwrite, Incremental Jobs are set to Daily backup and Append or terminate.

Thank you

[SuperBrain]

would have to overwrite the existing Full, so would the incrementals taken before the new Full continue to be valid?

Not any more, since you already have a new Full backup.

In order to do this, do I need enough space on the backup NAS to hold two Monthly Full backups?

Because you will be overwriting the last full backup, you dont necessarily need that much space to hold two full backups.

I would have recommended taking Differential backups instead of incrementals coz differentials are faster and more reliable during restores.

Incremental	Differential
Fast Backups	Slow Backups
Consumes less storage space	Consumes more storage space
Slow and lengthy restore process (since full + every incremental set is reuquired during restore)	Fast and convenient restore process. (since full + only the latest differential set is required during restore)
Less reliable Imagine, due to some reason one of your incremental sets for corrupt. Since incre's are dependant on previous incre.	More reliable. Coz differentials are not dependant on the previous differential, they depend on the las full backup.

But, i understand the space constraint!

Have 2 Backup-to-disk folders:

ExchangeBackups
NAS Backups

Create 4 backup jobs as you planned and target Exchange Full & Incre to Exchange Backups and NAS Full & Incre to NAS Backups

Full Backup jobs = 4 weeks overwrite protected.
Incremental jobs = 4 weeks overwrite protected (in case of differentials you could have considered to reduce this to 1 week, since only the last Diff set is required during restore)

This should make sure you have

Full backup retention = 4 weeks
Incre backups retention = 4 weeks

Exchange and NAS backups are saved in seperate folders.

[FRuk]

Thank you very much for your response - I think I agree with regards to the Differentials and if there is sufficient space I will go with that.

In the setup you have outlined, would I be able to restore from differentials taken before the Monthly Full? For example;

Friday 4th May I take a Full backup
Every subsequent day I take a differential
Friday 1st June I take a Full backup, overwriting the May Full
I continue to take differentials

On the 12th June, a user realises that a file is missing or corrupt, and the last time they saved it was around the 20th May. I still have this differential - would I still be able to restore data from it even though I have overwritten the earlier Full backup?

[SuperBrain]

Incremental and Differential backups are not independent, they are both dependent on previous backup sets.

Incrementals are dependant on the previous backup set (Full/incremental)

Differentials are always dependent on the previous Full backup.

FULL A1 --> Diff A1 ---> Diff A2 --> Diff A3 --> Diff A4 --> FULL B1 ---> Diff B1 --> Diff B2 --> Diff B3

Diff B2 cannot be restored with FULL A1... Diff B1, Diff B2 and Diff B3 will need FULL B1 coz they are dependent on Full B1

[Kiran_Bandi]

Incremental Jobs are set to Daily backup and Append or terminate.

Do not append disk backups. Because there is no advantage in doing so. Configure B2D jobs to Overwrite and corresponding media sets with 0 Hours Append Period.

If you keep on appending to your incremental backup base file, chances of it getting overwritten will be very less / most likely zero.

You might want to read my BLOG about B2D configuration: https://www-secure.symantec.com/connect/blogs/faq-how-configure-media-setsb2d-jobs-and-backup-exec-proper-management-disk-space-while-using-