Re: 2-tape drive testing

[Luis Bernardo <bernardo@math.lbl.gov>]

On Thu, 1 Oct 1998, David M. Malon wrote:

> >  
> >  I was thinking a little more about the 2-tape drive issue.
> >  Rather than arange to have 2 drives put into one class
> >  of service so that an individual tape may go into either
> >  drive, what about just spreading files over 2 existing
> >  classes of service.  When we retrieve them, a given file
> >  will always go to the same tape drive, but we will
> >  know that the files are spread across at least 2 tapes.
> >  We can also do this without a reconfiguration of hpss.
> >  
> >  Doug
> >  
> 
>    Wouldn't this imply that Luis would need to know the class of 
>    service, rather than just the HPSS path, for every file?  I know he uses 
>    setcos with a fixed number in his pftp scripts now.  If Luis 
>    needs to write code to accommodate this approach, it becomes a matter of 
>    resources and time (GCA effort vs RCF effort?); I think Luis is also 
>    working on a couple of other issues (we've been running with cmanager.old, 
>    for example).  

I believe the problem with cmanager (not cmanager.old) was the script. I
changed "cmanager.old -g $1" into "cmanager $1" and it's running now.
Alex, what's that -g for? cmanager was not expecting that and that's why
it was crashing. That's what I think.

> 
>    Luis, what would implementing Doug's suggestion require on your part?
> 
In principle it would be quick to make changes to accommodate different
classes of service and different HPSS paths for different files. The issue
is where the CM would get that information from.


Luis


--------------------------------------------------------------
Luis M. Bernardo  <lmbernardo@lbl.gov> <www.lbl.gov/~bernardo>  
Scientific Data Management Research & Development Group
Lawrence Berkeley National Laboratory         
Berkeley, CA 94720