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New DAOS features in Notes/Domino 8.5.1

Technote (FAQ)


What is new in Notes/Domino 8.5.1 with DAOS?



Starting in Lotus Domino 8.5, the Domino Attachment and Object Service (DAOS) was introduced to provide the ability to store one copy of an object at the file system level for access from all DAOS-enabled databases on a server. Domino 8.5.1 takes advantage of this functionality in the reply/forwarding of attachments and replication of attachments.

When creating, replying or forwarding a message with an attachment, the client will send the DAOS key of the attachment to the server to see if it already exists in the server's DAOS store. If so, there is no need to send it over the wire when sending the note. Because it already exists on the server, the existing DAOS objects reference count is incremented. If the DAOS key does not match an object in the server's DAOS store, then the object is sent to the server when the message is sent. In testing, this has shown a 250MB attachment going from minutes to send to a second because only a DAOS "ticket" needs to be sent. This process of only sending over the ticket and incrementing the reference count of the existing DAOS object is referred to as "remote cloning".

Similar processing happens during replication (this includes cluster replication) so that if a note with an attachment is to be replicated to another server and that destination server has the attachment in its DAOS store already, then only a ticket needs to be sent between the servers instead of the entire attachment.


  • Domino servers and Notes clients must be at Release 8.5.1
  • Databases must be at ODS51. This includes local and server databases as well as files. It also includes the local autosave database if a client has the autosave feature enabled.
  • Server databases must be DAOS-enabled
  • The object that is being processed needs to be over the minimum configured size for DAOS objects on the destination server


There is no configuration that needs to be done to take advantage of these new features. They are on by default when the requirements above have been met. If "remote cloning" can not take place for some reason the client/server will just use the old way of sending the object across the network.


Two new stats have been created to monitor the savings from cloning. These new stats will not appear in the 'show stat' output until an object has taken advantage of cloning.

DAOS.Object.Attach_DAOSCloneRemote -- lists the number of objects on the server that did not need to be sent over the network from remote clients or servers because they already existed in the local DAOS store.

DAOS.Object.RemoteCloneBSavings - total savings in MB for objects that did not need to be sent over the network from remote clients or servers. Note - this uses the size of the resulting .NLO file that the attachment is represented by.

Document information

More support for: IBM Domino

Software version: 8.5.1

Operating system(s): AIX, IBM i, Linux, Solaris, Windows

Software edition: All Editions

Reference #: 1411307

Modified date: 14 January 2010