[AFS3-std] Quota for max. number of files per volumes

[Felix Frank]

Simon Wilkinson wrote (Mon Jul 13 2009 23:39:06 GMT+0200 (CEST))
> 
> On 13 Jul 2009, at 22:26, Alf Wachsmann wrote:
>> I would like to open the discussion about these changes since they
>> will have to be dealt with for the RXOSD changes anyway but provide
>> by themselves already a very useful feature.
> 
> Rather than overloading existing fields (especially in the case of 
> returning two values bitpacked into MinQuota), I think it's more 
> valuable to consider the RPC changes necessary to support this as a 
> first class feature. Fortunately, this would  appear to be relatively 
> simple. We would need to to revise GetVolumeStatus and SetVolumeStatus, 
> and the structures AFSFetchVolumeStatus, and AFSStoreVolumeStatus.
> 
> I will leave others to speak to the desirability of using the MinQuota 
> portion of the volume header - I've got no idea how widespread other 
> uses for this field may be.

Oh it's useful alright - many HEP sites supposedly use AFS as grid and 
farm computing storage, and thrashing due to misbehaving parallel jobs 
(that create huge numbers of files in single volumes) is a probably 
common issue.

Bear in mind that not only are additional RPCs needed, but the volume 
dump format must be extended as well. I expect such an extension to be 
on the agenda for the upcoming protocol upgrade?

Cheers
  - Felix