Check if a tape pool needs more tapes

Site Administrators
1

Hello,

Can you please let us know how does CERN’s CTA team check whether a CTA tape pool needs to tbe topped up with more empty tapes?

Thanks,

George

2

Hi George,

we have simply adopoted the mechanism from CASTOR to CTA.

We check if the number of free tapes is less than number of partial tapes and if yes, we add more tapes. The new tapes are taken from supply tape pools as defined in the supply column.

Cheers,

Vladimir

3

Check also this discussion:

4

Hi Vlado,

Many thanks for the quick reply. Would it be possible to share the scripts you mention in the above thread? My email is george.patargias@stfc.ac.uk

How do you deal with older, unused, tape pools? If these tape pools contain empty tapes
then these tapes will be waisted. I think we have considerably more pools (~180) than CERN which can only make the waste bigger. Unless yout script checks for something like “last usage time” of the tape pool and moves away the free tapes if the pools are older than a certain age.

Best,

George

5

George,

I was told that you (somebody from RAL) should have access to see our CTA operations repository in Gitlab. Is that the case?

Regarding the unused tape pools, indeed if you have many of them there is a lot of wasted space. That is why we try to keep the number of tape pools to lower number (to be reviewed for Run 3).
And what we do with them? We simply repack those almost empty tapes and merge them to larger pool. Something like CMS_before_Run2.

Vladimir

6

Hi Vlado,

I am not aware of your CTA operations repo in gitlab. In a recent email, Steve referred to this
https://tapeoperations.docs.cern.ch/ctaops/
but I cannot seem to access it; I get a “Secure Connection Failed” message.

Best,

George