The ZODB blobstorage directory contains a .layout file with the string \'lawn\', \'bushy\'.
What is the difference between the various blob storage directory formats
It is explained here: http://svn.zope.org/ZODB/trunk/src/ZODB/tests/blob_layout.txt?rev=101802&view=markup
FTA:
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Blob directory layouts
The internal structure of the blob directories is governed by so called
layouts. The current default layout is calledbushy.The original blob implementation used a layout that we now call
lawnand which is still available for backwards compatibility.Layouts implement two methods: one for computing a relative path for an OID and one for turning a relative path back into an OID.
Our terminology is roughly the same as used in
DirectoryStorage.
It also explains the formats in detail.