RE: db to HPSS

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

At this moment the CM expects one directory on both HPSS and local disk.
Changes are not very simple but are certainly possible. In principle
it would be easy to change the CM to handle multiple directories on HPSS.
The only problem is the DB file <-> HPSS file mapping. The "obvious" way
would be to use Objectivity for that but that would require the use of
oochangedb after the transfer and we decided a few months ago not to do
that. On local disk things are a bit more complicated. Although the CM can
put the files wherever Objectivity says they should be the QM expects them
to be in the same disk (directory). Otherwise the QM may request the
purging of a file from the wrong disk. In other words, the interface
between the CM and the QM needs to be changed if we want to handle files
in multiple directories in multiple (local) disks. 
Luis


On Sun, 11 Oct 1998, Douglas Olson wrote:

> The cache manager expects all files for a federation to be in
> the same directory in HPSS.  It uses the Objy catalog
> for placement on disk. We have only tried this
> (to my knowledge) for all files, of interest
> to the cache manager, being in one directory
> also. Perhaps it is smart enough to handle
> files in arbitrary directories.
> Luis, do you know?
> Doug
> 
> > -----Original Message-----
> > From: Torre Wenaus [mailto:wenaus@bnl.gov]
> > Sent: Friday, October 09, 1998 7:02 AM
> > To: Doug Olson
> > Subject: db to HPSS
> > 
> > 
> > Hi, we're bumping against the ceiling on /disk1 and are moving the STAR
> > federation files to HPSS except for a few files.
> > 
> > Can the GC software be given a DB file <-> HPSS file mapping so 
> > that we can use
> > GC retrieval from the HPSS locations we're dumping them to, or 
> > does GC have to
> > move them to GC-controlled HPSS locations?
> > 
> >   - Torre
> > 
> > -- Torre Wenaus, BNL      wenaus@bnl.gov      516-344-4755  Fax 
> > 344-4206 --
> > -- STAR Experiment, RHIC@BNL Computing and software project 
> > leader       --
> > -- B. 510A Room 1-175        
> > http://www.rhic.bnl.gov/STAR/computing.html --
> > --                 
> >           http://www.wenaus.com/torre.html            --
> > 
> > 
> > 
>