cancel
Showing results for 
Search instead for 
Did you mean: 

Help understanding & setting up Synthetic backup

dfosbenner
Level 4

I have a Windows Server 2008 R2 server, backing up to a NAS device using BE 2010 R3.  I need some guidance on how to setup the jobs in the policy, and when to run them.

I made a copy of the default Synthetic Backup policy.  It has three jobs, Baseline, Incremental, and Synthetic.

I understand what Baseline and Incremental do.  I assume I'd run the baseline once.  I want to run the incrementals every hour from Mo-Fri during 8a-6pm.  Make sense?

My confusion is with the Synthetic backup - how often should this be run, and what does it do?

ALSO - Should SYSTEM STATE be included in incremental backups?  From what I'm reading, there's no "incremental" backup of the System State, so it's a full backup each time.

Thanks!

9 REPLIES 9

Dev_T
Level 6

Hello,

The below link might help you to setup
Synthetic Backups

http://www.symantec.com/docs/HOWTO21791

ALSO - Should SYSTEM STATE be included in incremental backups?

We cannot perform Incremental OR differential backups of System State...Its always a FULL backup

As per the below link:

http://www.symantec.com/docs/TECH52013

Backup Exec will only support System State Synthetic backups for Windows 2000, not Windows 2003 or later.

Download the Admin Guide from the below link and refer page # 899 to know more about Synthetic backups

http://www.symantec.com/business/support/index?page=content&id=DOC2211&key=15047&actp=LIST

Hope this helps...

dfosbenner
Level 4

I don't mean for this to sound unappreciative, but your post wasn't very helpful.  First, I've already read the Admin guide, and the links you mentioned before I posted.  None of these answer my questions.

It is STUNNING how little comprehensive information there is on the subject of synthetic backups by Symantec.

I KNOW that you can't do an incremental of the system state, for instance.  But I would like to have incremental backups run hourly.  If I include the System State in the backup, it's a 7GB backup before any data is backed up.  I want to transfer my backups offsite nightly, and at this size, that would be impossible.  So the question is SHOULD the SS be included in incremental backups?  If not, how does that work.

As for synthetic backups - what is their purpose?  What do they do?

After wasting a few days on this I'm starting to look at Acronis and other products, because I honestly don't think BE is capable of doing what I want.

It is incredible how much material is in the Admin guide, yet how unhelpful it is.  I say this as a >10 user of BE.

teiva-boy
Level 6

For the most part synthetics are used for flat files only.  Not for applications, databases, or system state backups.

So you would create a policy selecting only flat files, and a separate policy for all else including system state, etc.

Frankly for synthetics, it's not that great, and chokes on large file counts where the synthetic portion takes longer than the actual full itself.

It's also only included when you buy the "Advanced Disk based option."  It should be free!  

 

Now I've never heard of incrementals run once an hour.  Typically once a day.  If you are looking for once an hour, you should be looking at snapshot based backups or CDP type products.

pkh
Moderator
Moderator
   VIP    Certified

I don't think ADBO is free.

pkh
Moderator
Moderator
   VIP    Certified

Most installations will run incremental backups daily, not hourly.  As such, you need to include the system state so that you can have the latest state of the OS.  When you restore the system, you restore the full and all the incremental backups with its system state to arrive at the last version/state of the machine.  If you don't include the system state in your incremental backups, then you are back to where your machine was at the time of the full backup.

Synthetic backups are used so that you don't have to have take full backups from your machine.  You construct a full backup using your actual full backup and your incremental backups.  That is why it is called synthetic backup.

teiva-boy
Level 6

Who said it was?

dfosbenner
Level 4

Thank you everyone for the more informative repsonses.  Here's the core issue for me: System State backups are about 7gig.  Even if I did one incremental per day, that's 7gig I need to transfer off-site, not even counting any data.  It doesn't look like it's going to work too well, I just don't have the bandwidth for that.

I think I'm going to have to look at snapshot-based options.  I assumed BE would have had this as an option at this point in it's lifespan, but I guess not.

Again, thank you for the replies.

Colin_Weaver
Moderator
Moderator
Employee Accredited Certified

If you are looking at a image level DR capabiolity instead of a File System based process then you should look at Symantec System Recovery (orginally Backup Exec System Recovery)

 

However going back to Synthetics for a moment

1) You do need  an ADBO license

2) You need lots of disk space and/or 2 tape drives in your library (lots of disk space for the B2d is recommended option)

The way it works in order is

a) Baseline (Full Backup runs)

b) One or more Incremental backups run

c) A Synthetic Backup is run and combines the backup data from a) and b) to make a full - this obviously needs all the backup sets to be available and also to have a spare target device (hence the disk space/ tape drive requirements)

d) further incremental backups are run

e) Another Synthetic backup is run that combines the data from c) and d) to make a full

f) Repeats steps  c) d) e)

 

Note as the recommended configuration involves using a B2D target, then this is usually combined with duplicating the Synthetic backup to tape as and when required.

teiva-boy
Level 6

Colin, can you address the issue where large file counts would make the (step c) 2nd week full (synthetic) take longer than the actual traditional full?

We've talked about this in the past, and it was an issue since at least v12, and still not fixed.  There was an internal hotfix that was not available to general public, and was a QA/Dev thing only only *if* you met certain criteria.

I'm talking file counts of only 50k files+..  Not large by any count, but enough to drag the system down for whatever reason.