[Zope-dev] Request for comments: Directory storage

Petru Paler ppetru@coltronix.com
Wed, 7 Jun 2000 18:00:31 +0300 (EEST)


          Hello all,

   You probably saw my yesterday post with the first alpha of
ReiserStorage. One of the questions that people tend to ask about it is
wheter they can use it without reiserfs.
   There are two problems with not using reiserfs:

1. ReiserStorage (now renamed to DirectoryStorage) stores each object in a
separate file and *all* the files in a single directory. This was done in
order to let the filesystem what it was meant to do: store and retrieve
files quickly. While reiserfs is *extremely* good at this (it uses a btree
to store directory entries), most other filesystems do linear searches
when finding a file so performance is very bad when you have many files in
a single directory.
   This problem can be solved by splitting files into multiple directories
when not using reiserfs. This would add a little overhead but it is
tolerable.

2. Waste of space. Typical block-allocation filesystems like ext2 and FAT
will waste alot of space in the usage pattern of DirectoryStorage.
ReiserFS packs small files together in the btree, so it solves the
problem, but I have no ideea how this could be fixed easyly on the other
fs's.

Comments ? Suggestions ?

PS: a new DirectoryStorage release will be done today, with bugfixes and
new features.

-Petru