[glue-wg] RetentionPolicy definitions

[Maarten.Litmaath at cern.ch]

On Tue, 15 Apr 2008, Burke, S (Stephen) wrote:

> Maarten.Litmaath at cern.ch [mailto:Maarten.Litmaath at cern.ch] said:
> > What would be a use case for MaxPinDuration?
> 
> You may know that you will want to pin files for, say, 1 week, so you
> could exclude SEs which don't allow that. However, if it can depend on

I see that more as a negotiation between the VO and the SE admin:
if the SE remains unusable, the VO will just blacklist it.

> the user then maybe that isn't so useful. Could it still be useful to
> have a boolean to say that pinning is supported, or do we expect that
> all SEs will support it?

Well, the Classic SE does not support it, and it may have a part of its
name space going to tape.  But do we care?  Furthermore, in SRM v2.2 a
pin may be taken as advisory: when CASTOR needs room for other files,
it will remove pinned files that are unused, while dCache currently will
honor the pins instead.

> > I did not see any other SRM parameters, but I think we need 
> > to resurrect MaxFileSize and probably MinFileSize as well.  In the
> StorageService?
> 
> Are they set for the SRM as a whole?

Quite likely.  In principle it might be using different file systems
with different maximum file sizes, but I doubt anyone will ever do that.

The minimum file size might also depend on the tape library (CERN indeed
has 2 instances with different minimum sizes), but that is for the SRM
to sort out: the user still has a single minimum file size.