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Last Tape Drive is not used
Hi Guys,
I have 3 tape drives and when a clone is using 2 tape drives, or a backup is using 2 tape drives, the last one available tape drive, regardless of which one of those 3 is, is not used anymore, until 2 tape drives are free, then the backup in queued or active state will run, why is that?
Current config Tape Library:
AutoMM - ON
Max Parallelism 3
Number of Drive/Devices 3
Target Session on all 3 Tape Devices is 6
Max Session on all 3 Tape Devices is 32
Max nsrmmd count is 1
NW version 8.1
So why is not using the last single Drive available to write when I have a group waiting to run
some save sets are in queued state
some save sets are in active state, but not ruining, only waiting
What i`m missing?
bingo.1
2.4K Posts
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October 9th, 2017 02:00
The jukebox 'max parrallelism' is usually the parameter which controls that. By default it is set to "number of tape drives -1" - this shall ensure that you still have one drive to recover while the others run backups. However, it seems that you have increased the value to use all 3 tape drives for writing.
Could it be that you have assigned devices to pools and that you have not selected all of them?
GeorgeDicu
7 Posts
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October 9th, 2017 04:00
Hi, I know, I dont want that, I want to use all 3 regardless, Even if I set it to 3 it wont use all 3 tapedrives, do I need to reboot nsrsnmd?
Also, I see that LTO3 cannot sue more than 1 nsrmmd, which might limit the savestreams to go on the 3rd drive even groups are waiting to run.
I have only one nsrmmd for all 3 TapeDrives, and I know one nsrmmd is ususally handling 4 savestreams. for the 5th it needs new one.
Any workarround?
bingo.1
2.4K Posts
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October 9th, 2017 09:00
The reason why not all drives will be used could have a bunch of potential origins - the jukebox parallelism was just one of them. However, as we do not know your config, the reason is not easy to find.
"... do I need to reboot nsrsnmd?"
I don't understand. You do not reboot a daemon. It is started indirectly by the NW server process.
"... I have only one nsrmmd for all 3 TapeDrives"
This is what makes me thinking. There should be at least 1 nsrmmd process for each configured and enabled device - it does not even need to be connected (any longer).
GeorgeDicu
7 Posts
0
October 18th, 2017 00:00
Hi Bingo,
Jukebox parallelism is now set to 3 out of 3, so in my case it shouldn't care that I need to restore so I need one tape Drive free.
In the case of nsrmmd, I think this is the normal behavior in all LTO generations.
Any other ideeas?
//George