On Monday 12 January 2009 07:48:17 am ISP Lists wrote:
> Can someone please provide a brief discussion as to when a vpopmail hashed
> folder tree becomes "big enough" to warrant backfilling?  Or, is "big"
> just one concern amongst others such as: "rate of deletes and adds",
> "filesystem choice"...
> I'm not quite picking up why the backfill is important.
Well, I don't know what other people are considering "too big", but I actually 
wrote a backfill patch when I was working at a medium-sized college.  We kept 
all 62 top-level hash directories on separate partitions, but didn't ever 
want to go to second level hashes - and with ~1200 adds (incoming freshmen) 
and deletes (outgoing seniors) every year, this became an issue pretty quick.  
The other issue with "backfill" is that the current implementation makes it 
so that you can easily exceed the 100 users per hash dir limit by deleting 
users from prior hash dirs and then adding new ones since the only check for 
a new hash dir is "total users/100".  My patch and the reasons therefore can 
be found at 

The main reason it's not currently slated for inclusion is that it's for the 
mysql backend only, and whatever process is used to provide backfill must be 
available for all backends.

One last note - the idea of maintaining a list of backfill "slots" in a text 
file is a pretty good one, but it still doesn't address the issue of not 
properly calculating the number of users in a directory...

Joshua Megerman
SJGames MIB #5273 - OGRE AI Testing Division
You can't win; You can't break even; You can't even quit the game.
  - Layman's translation of the Laws of Thermodynamics


Reply via email to