Directory Hashing
*****************

Cyrus IMAP uses directory hashing for per-user state information,
including quotas (with "quota_db: quotalegacy"), sieve, subscriptions
and seen information.  Sites with lots of users may wish to hash their
mail spool, too.  Cyrus provides mechanisms for this.  This pair of
settings for imapd.conf(5) control hashing behavior:

   "hashimapspool:" 0

      If enabled, the partitions will also be hashed, in addition to
      the hashing done on configuration directories.  This is
      recommended if one partition has a very bushy mailbox tree.

   "fulldirhash:" 0

      If enabled, uses an improved directory hashing scheme which
      hashes on the entire username instead of using just the first
      letter as the hash.  This changes hash algorithm used for quota
      and user directories and if *hashimapspool* is enabled, the
      entire mail spool.

      Note that this option CANNOT be changed on a live system.  The
      server must be quiesced and then the directories moved with the
      **rehash** utility.

Regardless of those settings, the per-user state information will
always be hashed.
