Maximum number of parallel data transfer and Device Streams

Hi @TD89 

Thanks for reaching out.

Please review our section on streams in our documentation which would assist in making this decision.

The reason I’m suggesting this, as there are a number of places where stream allocation would be affected.

May I please also ask the reason behind this chance, are you getting errors during busy backup windows? If so please share them and we can make some suggestions based on this.

Hello @TD89 

The Data Steams is the limit of how many streams can be active at a given time on the MediaAgent. Policy Streams is the limit of how many streams can be used by a Storage Policy.

So theoretically you can have 3 policies using 100 streams each on the same MediaAgent.
You don’t need to increase the policy streams, but you could if you have that much activity on the Policy you can increase them.

Thank you,
Collin

@Emils Hi Emils, thank you for the info. Yes, when there are too many backups run at the same time, some of the jobs would show pending or waiting. It has the error message but I forgot what it was. Then after a while they would start to run again. Moreover, when the job stream hits 500, some jobs will fail. I have to stop the tape aux copies to let other backups run.

Hello @TD89 

We can configure number of active streams on  Commserve, Media Agent, Storage policy and Client level. Increasing stream limit may increase the system resource utilization.   
 
To increase the number of streams for concurrent backups from a large number of clients, enable the option optimize for concurrent backups. It will increase the current stream count limit by 200 more streams.

Procedure

1. From the CommCell Browser, go to Storage Resources > MediaAgents > MediaAgent.

2. Right-click the MediaAgent that you wish to optimize for concurrent LAN backups, and then click Properties.

3. The MediaAgent Properties dialog box appears.

4. On the Control tab, in the Data Transfer section, select the Optimize for concurrent LAN backups check box.

5. Click OK.
    
   Please check the below documentation links for further information.

Managing Concurrent Jobs
 
https://documentation.commvault.com/commvault/v11/article?p=8644.htm
 
Setting the Maximum Number of Simultaneously Running Streams
 
https://documentation.commvault.com/commvault/v11/article?p=6352.htm
 
Multi-Stream Backup Operations
 
https://documentation.commvault.com/commvault/v11/article?p=10978.htm
 
Increasing Streams for MediaAgent
 
https://documentation.commvault.com/commvault/v11/article?p=8641.htm 

Hi @Tanuj Balani my High Watermark is 500 currently, do you think I should increase it? Honestly I don’t have any issue with the current settings, but since the tape aux copies are trying to catch up, they take too much streams, and they are running super slow. Most of the time, I have to suspend all the tape aux copies and just let 1 run to have the speed about 1000gb/hr. When all the tape aux copies running together, the speed is really slow around 200gb/hr maybe less. Do you you know how I could improve it without suspend them manually?