B2D settings and best practice

[maxim_petrov1]

Hi everyone,

I have a very simple question: I have to backup 9TB of data to a B2D folder on a daily basis - one full backup on saturday and differential Mon through Friday. What would you recommend to set the file size to and how many backup sets do you think would be best to use?

Currently the max file size is set to 52GB and the number of files is 100, and it is set to allocate the maximum space. The issue is that nearly after every backup we are running out of space, and have to manually drop the backup files.

Any input is appreciated. 

[Ken_Putnam]

How much space is available on the target disk?

In BackupExec speak, a "backup set" is one share, or one database, etc  How many sets are there in your selection list?

Are your jobs all "overwrite" or are they 'append, else overwrite"? 

[CraigV]

Hi,

First question is how big is your B2D folder, and the second question is if you're running BE 2010, why are you not considering deduplication for that? It's going to cut down backup sizes quite a bit over time...

Below are a TN for the dedupe best practices, and the link to additional information:

http://eval.symantec.com/mktginfo/enterprise/fact_sheets/b-datasheet_be_2010_deduplication_option.pd...

http://www.symantec.com/business/support/index?page=content&id=HOWTO21767

As for your B2D, it depends on how you need to set up your environment. Having bigger *.bkf files means speeds should be a bit quicker as it streams for longer. The downside is the amount of space taken up.

Thanks!

[teiva-boy]

Make sure to format using the largest RAID block sizes, and the largest NTFS allocation unit size for the best performance.  

[maxim_petrov1]

Thanks everyone for the input! I have to make a slight correction though: we are backing up 4TB of data - that is a full weekly backup, daily incremental are 300GB to 2TB, it is 9TB that is available on the target disk.

The OPP for full backups are set to 4 weeks, allows 12 hours append. Also we have it configured to append, else overwrite.

The backup to disk folder is 5.1TB, as it has 98x52GB bkf files.

We had issues with dedup, and symantec support suggested to wait till release 3 is out and update to it, which we are doing at the moment.

My main concern was regarding the size and the amount of bkf files, either leave them at 52GB, or increase the size to at least 500GB.

[CraigV]

...if you set it too high, you could run into performance issues to do with memory allocation. 500GB might be too big unless you have 1 seriously powerful server (CPU and RAM).

Try 100GB and see what it gives you.

Also, you might want to set your OPP period down a bit...if the OPP is set too high, your media won't be cycled to scratch as fast as you would need it.

You might also want to check and make sure you're not reserving too much space for free space...the level that backups stop once the B2D hits that threshold. If for example, it was set to 90%, change it to 95% and see what happens.

The other option is to change your RAID setup...so move from RAID1 to RAID5 for example...

[Ken_Putnam]

If you bump the size up to 500GB, and need to write 501 GB, or 1001 GB, you wind up losing 499 GB of disc space.  I'd leave it or even lower it some, since I recommend only overwrite jobs when using a Disk  target

If your weeklies are 4TB and you only have 9.1 TB available on disk, it doesn't make much sense to have a 4  week OPP for the weekly media set, since you cannot even fit three full jobs, much less four, and that is not even counting the dailies