Showing results for 
Search instead for 
Did you mean: 

Backup Performance Help

Level 2

I am trying to tweak some more backup performance on one of my servers and was hoping for some ideas.

Here is the setup.  I have a windows 2003 server that has Symantec Enterprise Vault installed on it.  One of the drives currently has 1.1TB of data on it.  A full backup of that drive directly to tape (as I have no other option) takes 49 hours.  I am receiving 6424 KB/Sec on the bacup job.

I am running NB 6.5.4 and the data connection between the media server and vault server is gigabyte ethernet.  I have 6 tape drives available but I can only get it to use one.  I have multiplexing and multiple data streams turned on.  My current multi-plexing is set to 4 and I have tried other values to try to speed up performance with no measurable change in results.

I don't know of anything else to try so I am open to all suggestions.



Partner    VIP   
You might want to consider using flshbackup for you're enterprise vault. Flashbackup works on  block by  block basis instead of file by file. The result is vastly reduced backup time, the down side is a full backup is always the entire disk meaning empty space is being backup as well.

Regrading the multistreaming problem: Do you use some sort of wildcard like * for backup selection e.g e:\vaultdata\*

Also check the "max job per client" is set to something larger than one. You can check "max job per client" in the Global attributes section of the master server.

Level 6
Employee Accredited
Nicolai makes some good points, however.

"One of the drives currently has 1.1TB of data on it.  A full backup of that drive directly to tape (as I have no other option) takes 49 hours."

A couple of things are not clear :

Are you concerned with only backing up that drive ?  That is, the other drives backup quickly, perhaps they are much smaller.
Multiplexing is used to allow more data from multiple disks or even machines to go to a drive, thus allowing the drive to stream.  Certainly in this case you need to be getting your drive to write quicker else the shoe-shine effect you will have is damaging, this is dependant on the drive type, some drives are designed to stop-start and suffer no adverse effects. will not backup that one drive quicker - the limit is either the speed that data is coming off the drive, the network or the tape drive.

You could run a bpbkar -nocont test to test the speed at which the bpbkar process can read data.  What ever this figure is, if, low, is a limiting factor.
Next FTP 100MB from the client to the media server, this is the network performance speed.
Finally, write data from the media server to its own drives, this will probably be very fast (depending on the speed to media server can get the data off the disks.

If I had to guess, I suspect that the llimit is caused by the speed the win 2003 machine can get the data off the disk.  Not really that much you can do about that in NBU, apart from using flash, which would increase the speed.  The other option is to put the data on striped disks, it might help.  However, if there are many many small files, this is a limiting factor with any backup software, and the reason flash is used.

Multiplexing off one drive is bad, as the drive heads are flying all over the place and in fact the backup will be slower.

However, you say a 1TB drive, is this in fact a 1TB lun made up of multiple spindles, in which case as long as each stream is pulling data from a diffrenet spindle, although in the same LUN, multiplexing would help.


Level 2
Thanks for the responses.  Based on responses, I don't see too many options.  I had suspected that I wouldn't be able to do much.  I will however look at flashbackup..

Just to answer a couple of Martin';s questions.

I do backup the entire server but the system state, c: & e: drives are in a different stream and aren't very big.  They backup fine.
The drive in question is actuall a 2TB SAN drive spread across multiple spindles so I don't think disk performance is the bottleneck.
I believe the big issue is that since these are email archives there are currently 9,257,316 files on that disk.

Also for Nicolai.

Max jobs on the server is set to 6.
I am not using a wildcard, doing the entire drive as the vault data is the only thing on that drive.