Cta-admin mountpolicy options

1

Hello,

Can you plese point me to some documentation with regards to the meaning of the various options of the “cta-admin mountpolicy” command?

    --archivepriority/--ap <priority_value>
    --minarchiverequestage/--aa <min_request_age>
    --retrievepriority/--rp <priority_value>
    --minretrieverequestage/--ra <min_request_age>

Thanks,

George

2

Hi George,
I was unable to find any documentation that explains the attributes of a CTA mount policy. I shall therefore try explain their meaning myself.

The archive and retrieve priorities of a mount policy are integer values where larger values have high priority than lower values.

The minimum archive and retrieve request ages of a mount policy are the minimum ages in seconds a mount request has to be in order for it to be eligible for a mount independent of how much data the mount represents. CTA mounts have to satisfy two independent and sometimes competing requirements. In theory a tape should only be mounted when the amount of data to be transferred warrants the time “wasted” physically mounting and dismounting the tape. In practice end users should have their tapes mounted after a configurable amount of time independent of how much data will be transferred.

Regards,

Steve

3

HI Steve,

It all makes sense; thanks for this!

I just found the very good talk on CTA tape scheduling that Cedric had given in the March EOS work.

Best,

George