Multiple Copies and Tape Multiplexing

[Bogdan_Visinesc]

Hi all,

I am trying to use multiple copies within a schedule to send backups to tape and to disk in the same time. The problem is that when I use this setup, there is no multiplexing on tape or disk going on. I have two clients in a policy. When I send data to two disk storage units, or to two tld storage units, both clients backup in the same time (thus multiplexing happens). Whenever I use to send data to a disk storage unit and to a tld storage unit, the jobs start for one of the client, and are queued for the second client (thus multiplexing does not happen).
The tld storage unit has two drives (one of them was disabled during the test using also a disk storage unit), and has a setting of 8 maximum streams per drive. The disk storage unit has a setting of 8 maximum concurrent jobs.
What can I do in this situation?
Is this a bug or a feature? (Multiplexing works when using two tapes, and when using two disks, but does not work when using a tape and a drive).

Best regards,
Bogdan

[h_m]

Try a policy per client, and run both policies at the same time to see if it multiplexes to disk and tape.

[Bogdan_Visinesc]

I have tried your suggestion. It does not multiplex.

thanks,
bogdan

[DavidParker]

Bogdan,
What are the maximum allowed jobs set for each of your storage units?
If that setting is too low, it could be causing your problem.

[Dennis_Strom]

there is a max multiplexing setting on the storage unit also.

[Stumpr2]

This is old but much of it still applies

Why is VERITAS NetBackup is only allocating one tape drive for backup per policy/class?
http://support.veritas.com/docs/233150

Detail:

There are several parameters that affect the number of drives a media server may use during a backup. These parameters include:

1. Maximum jobs per client (this parameter controls the number of jobs that start per client):

In 3.4.1: Use Configure NetBackup GUI

In 4.5: Use Host Properties

Go to: Master Server -> Properties -> Global NetBackup Attributes -> Maximum Jobs per client

2. Maximum concurrent drives and maximum multiplexing per drive:
a. Maximum Concurrent Drives (this parameter will control how many drives any one storage unit will use)

b. Maximum multiplexing per drive (this parameter will control how many streams one drive will accept)

In 3.4.1: Use Storage Unit Management GUI

In 4.5: Use Console Storage Units.

Go to: Storage Unit -> Storage Unit Properties

3. Limit jobs per policy and media multiplexing:

a. Limit jobs per policy (this parameter will control how many jobs/streams the class can run at one time)

b. Media multiplexing (this parameter will control how many jobs/streams the class can multiplex on one drive)

In 3.4.1: Use Backup Policy Management GUI

In 4.5: Use Console Policies

Go to: Policy/Class -> Attributes -> Limit jobs per policy
Go to: Policy/Class -> Schedules -> Media multiplexing

[Bogdan_Visinesc]

Hi David, Dennis, Bob,

From the start of my tests, I have the following settings:
- Maximum jobs per client: 4 or 6;
- Maximum streams per drives: 8; (tape storage unit)
- Maximum concurrent jobs: 8; (disk storage unit)
- Limit jobs per policy: not set; (this should mean unlimited)
- Media multiplexing (inside the schedule): 8;

I am using 2 clients in one policy. When I set up 2 copies to go to the same disk, it works concurrently. When I set up 2 copies to go to the same library, it works concurrently (I have 2 tape drives in the same library). When I set up 2 copies to go to library and to disk, it does not work concurrently (I have setup Maximum concurrent write drives to 1, so that it only uses one drive), and the jobs for the second client are queued until the first one finishes.
Is this a bug or a feature? It cannot multiplex both to tape and to disk at the same time?
We are using NBU 6.0 MP4 on a SLES 9 server.

Many thanks for all your support,
Bogdan