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first pass on HPSS requirements for the June test

Greetings Challengers

> Here are a first round of thoughts on HPSS requirements for the June test:
> I have no idea what is reasonable to request at NERSC so Ill just write a wish list.
>
> 1) A COS devoted to the GC which will be available to us from MidMay and exclusively to us
> during the test
> period.
> 1a) Actually it might be nice if the COS were completely ours from MidMay until after our test
> so that we would not have to worry about sharing tapes with other users.
>
> 2) The ability to reconfigure the number of drives associated with that HPSS during our test
> period.  I would guess that we would like at least 4 drives available to us for certain tests,
> but that is a question for the team.
>
> 3) A "reasonably sized" (Im not sure what this means for GCA during scalability testing) disk
> cache located near the HPSS in a network sense.  I realize this probably isnt an nersc-hpss
> request, but it falls into the general category of GCA needs.
>
> 4) The ability to determine which files are on which tapes.  This could be via a printout of the
> contents of all the files on all the tapes in our COS although that would be helped if we could
> have the COS to ourselves.
>
> 5) File purging policy:
> Do not purge any file which has been accessed in the last 10 minutes
> Start purge when the cache is 5% full.
> Stop purge when the cache is empty.
>
> 6) Deferred dismount should be enabled.  That is, a tape will not be dismounted
> from a drive unless there is a request to mount a new tape in that
> drive.
>
> 7) We should have access to SAMMI so that we can monitor our tests.
>
> 8) Off the top of my head I cant think of any other issues.  Ill let you know if I come up with
> any additions.
>
> cheers
> david

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Hi Doug,
Here are a first round of thoughts on HPSS requirements for the June test:
I have no idea what is reasonable to request at NERSC so Ill just write a wish list.

1) A COS devoted to the GC which will be available to us from MidMay and exclusively to us
during the test
period.
1a) Actually it might be nice if the COS were completely ours from MidMay until after our test
so that we would not have to worry about sharing tapes with other users.

2) The ability to reconfigure the number of drives associated with that HPSS during our test
period.  I would guess that we would like at least 4 drives available to us for certain tests,
but that is a question for the team.

3) A "reasonably sized" (Im not sure what this means for GCA during scalability testing) disk
cache located near the HPSS in a network sense.  I realize this probably isnt an nersc-hpss
request, but it falls into the general category of GCA needs.

4) The ability to determine which files are on which tapes.  This could be via a printout of the
contents of all the files on all the tapes in our COS although that would be helped if we could
have the COS to ourselves.

5) File purging policy:
Do not purge any file which has been accessed in the last 10 minutes
Start purge when the cache is 5% full.
Stop purge when the cache is empty.

6) Deferred dismount should be enabled.  That is, a tape will not be dismounted
from a drive unless there is a request to mount a new tape in that
drive.

7) We should have access to SAMMI so that we can monitor our tests.

8) Off the top of my head I cant think of any other issues.  Ill let you know if I come up with
any additions.

cheers
david

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