Query about windows flashbackup speed

[prats]

Hi,

We are trying to configure Windows-Flashbackup at our site.Have never used the option before so not sure what to expect.With the flashbackup method we are trying to backup Enterprise Vault data.The Enterprise Vault agent is not installed.The backup does work but the throughput is just 5-7MB\sec.

I had read that since its a block level backup, the type of data to be backed up (small files etc) does not play a role during the backup.The backup method is "auto".

Is there any other configuration\tuning that I have missed out?

Regards

Prats.

[Sebastian_Baszc]

Hey Mate,

It looks like it is way too slow... Flash Backup is the raw partition backup, so in theory it should be as fast as your hardware configuration allows.

If you need to backup only a specific disk, you can use Snapshot configuration.

In this scenario - enable Shadow Copy on your client, in the Backup Policy, enable shapshot and select VSS, auto. Specify the drive you want to backup and run the backup. Compare the speed with your FlashBackup speeds.

Hope it helps.

[pikachu]

I am going to make a couple of assumptions in my reply:

• you know how EV&VSS work.
• this is not an environmental issue

First of "It looks like it is way too slow..." compared to what?

Flashbackup-Windows IS a raw device backup, but we map the drive as well. Say hello to our friend "VxMS".

I remember several months back I had a case with a company, who was trying to do the same thing. The issue on hand was that the backup was running around the same speed... if not even slower.

Let's talk about FBU-WIN and the shadow storage for a minute. Let's assume you have 10GB assigned for shadow storage and that the full backup takes 10h for you. During that time VSS has to create refrences to the shadow storage back to volume itself. Constant writing back and forth are happening, which in some cases could potentially bring down VSS. While the backups are running take a look at the drive itself you will see the drive performance on the drive goes to hell.

My suggestion to you would be to use some form of split mirror backups like Storage Foundation.

[Yasuhisa_Ishika]

FlashBackup is raw partition backup, but not completely free from handling files in it( let's say mapping).

I know a case that, if large gap(serial empty entry) exists in MFT, mapping operation takes long time.
See below for detail.

https://www-secure.symantec.com/connect/blogs/what-so-special-about-directread-registry-entry-flashb...
http://www.cecchetti.com/blog/?m=20110614 (Original KB is TECH52540, but it seems had gone)

[Anton_Panyushki]

Have a look at this https://www-secure.symantec.com/connect/blogs/presentation-some-flashbackup-windows-issues

You need to increase raw partition read block size in  netbackup client properties.