[Zope] DirectoryStorage and UFS2

[Ken Gunderson]

Howdy:

I'd have a Zope/Zeo site that I'd like to set up to use 
DirectoryStorage.  Platform is FreeBSD5.2.1 using UFS2 w/softupdates.  
Probably will also mirror with vinum.  DirectoryStorage docs state:

bushy:

If you are using a filesystem that is inefficient with directories 
containing larger than a few hundred items. This is optimal for most 
conventional filesystems, such as ext2 on linux. In this format each 
object is given its own directory nested inside 8 levels of 
subdirectory. Each revision of an object has its own file in that 
directory.

chunky:

If you are using a filesystem that is most efficient with directories 
containing tens of thousands of subdirectories, or hundreds of 
thousands of files. This is optimal for filesystems such as reiser3 or 
JFS on linux. In this format, one subdirectory is shared by up to 65000 
objects. That subdirectory is nested inside 4 levels of subdirectory.

I am unsure whether UFS2 would best utilize the "chunky" or "busy" 
options.  The 64 bit pointers allow for up to 65K subdirs w/in a dir, 
correct?  So the large number of subdirs under chunky format could be 
handled.  Dirhash and dirpref can deal can cope with large numbers of 
files per directory, correct.  But then doesn't UFS2 still use more 
linear model?  

Any insights from the FBSD/filesystem gurus would be appreciated.

-- 
Best regards,

Ken Gunderson
GPG Key-- 9F5179FD

"Freedom begins between the ears."      -- Edward Abbey