Legato 7 ignores Parellelism?

[WhiteWiz]

I have a small backup that i want to go to a single tape so i have set the parellelism of the client to 4 and the group to 4 and the target sessions of the tape drives is 4.
in Legato 6.2 this was all i needed to get my backup onto a single tape. But since i have upgraded to Legato 7 this doesn't seem to be working for me.
Am I missing something?

 

[605]

What do you want to tell us?

- Are there less streams going to the device and some to
another device/media?
If so, pool setup will most likely cause the error.

- Or are there more than 4 streams opened which NW will
then try to send to another device/media?

- Is there another group that provides save streams to
that device/media at the same time?

Actually, the only option that could really help ensuring
that the data will go to the same drive/media is when you
select 1 drive for the pool. Customers love this feature
although it is risky as well - it will prevent NW from
using another device in case of a failure.

 

[WhiteWiz]

More on this problem:
in legato 6.x the parellelism for a jukebox is measured in streams
in legato 7 the parellelism for a jukebox is measured in drives

 

[cyberted]

Can you give an explanation on this?

Thanks.

cyberted

 

[birky]

Yes, WhiteWiz please could you expand on your posting.

Seems a bit strange how it can be drives, would be interesting to know what you mean.

Thanks

 

[WhiteWiz]

I have 2 dives in both of my Dell Pv130t jukeboxes. If i try to set the parellellism for the jukebox to be 8 (4 streams x 2 dives) i get this message:
server backupsvr: max parellelism (3) cannot greater than number of drives (2)
(yes the real message has bad grammar)
Looks to me like the parellelism is measured in drives.

 

[cyberted]

Hello WhiteWiz,

I think the max parallism is sametihng different. Look in the Help of nwadmin.

If you want your save streams on one af your drives wautch out for the target sessions on the drive config.

How many target session are allowed on one of your drives?



cyberted

 

[WhiteWiz]

as i have said earlier their are 4 streams per drive.

 

[cyberted]

Have a look at the thread "Performance and paralellism".

There is a difference between parallism and target sessions.

Have also a look at client, group & server parallism .

We have config. jukebox max parellelism to 3 (4 drives).
From help: the attribute is normally set to one less than the number of devices within the autochanger.





cyberted

 

[605]

The jukebox parallelism does not have anything to do with
the number of save/recover streams opened but only with the
number of nsrjb commands. In other words: The jukebox p.
does not affect the number of data sessions.

Make sure that the server parallelism and the savegroup p.
have been set high enough