Optimizing parallelism

[Shayfever]

Hi,

What would be the optimal parallelism for a Unix clustered system with 28 nodes? Legato v6 Power Edition.

 

[john7]

Need more info....

Where are the tapes? on a backup server outside of the cluster or in the cluster?

How many file systems?

What does the network look like?

 

[Shayfever]

The tapes are on the Cluster. it is an 8 drive Compaq storage works carousel. There are 28 servers backing up Unix, VMS, NT/2000. The network looks like some one threw an egg high in the air and then let it hit the ground...Splat! All seriousness, we are backing stuff up globally.

 

[packageman]

Do you have different groups that start at different times? That, plus # of systems and filesystems, will determine the parallelism. You want to have as much stuff streaming to both drives for as long as possible.

 

[VicMcD]

Try setting the parallelism to 1 on each drive. Apparently this allows the software to decide which drives to use.

 

[VicMcD]

Sorry, should have said set "Target sessions" on each drive to 1

 

[cptb]

Setting target sessions on a device does not put a max to the number of sessions on the device. It's more like a minimum number of sessions. NetWorker will always try to get as high throughput as possible on a device using the server parallelism number of sessions. So, to decide on how you should set you parallelism check how many sessions you need to drive your devices with optimal speed for backups AND recoveries. A large number of backup sessions to one device will probably have the opposit effect on recoveries.