Paul Mooney presented on DAOS and let me use his presentation as a guide to summarize this new feature in Notes 8.5. To view the full presentation, visit Paul's website.
What is DAOS?
DAOS -- Domino Attachment and Object Storage -- is a process that is separate from Lotus Domino, but works with it, to remove attachments from documents. The process replaces the attachments with a "ticket" in the document. The ticket references the attachments that were originally contained in the documents; the attachments are then stored in Domino server's file system.
Note: The documents can be from any type of database, not just the mail database.
DAOS consists of four different components:
- DAOSManager -- DAOS Manager is the focal point of the DAOS feature; it runs under and separate from the Domino server.
- NLO -- NLO is the new file extension of any attachment the DAOSManager handles from a database. For security reasons, Lotus didn't copy the attachment and use its own extension. It's also important to note that it is an encrypted version of the attachment. The server's ID file encrypts the attachment. This does, however, create some of the following caveats.
- DAOS Catalog -- This is a Lotus Notes database that contains a list of the NLO files and their references. The DAOSManager process reads this database for information related to attachments it's managing.
- Tickets: These are the references that remain in the rich-text fields of Lotus Notes documents where DAOS removed attachments. They are used to reference the appropriate NLO files for that document.
Note: This database cannot be accessed by anyone directly. You will receive an error if you try.
Why should I care about DAOS?
The most obvious reason to run DAOS is the disk savings, especially in a mail environment where many attachments are exchanged. This has a domino effect where backups are smaller and backup times are shortened. Less resources are also required for backups.
What is required to use DAOS?
- Lotus Domino 8.5 server
- DAOS only works against attachments, not embedded objects.
- Space on a server where the attachments can be stored.
- Any database that DAOS manages must use the new ODS 5.1.
- Any database that DAOS manages must be transactionally logged.
- Any database that DAOS manages must have the new database property for DAOS enabled and then compacted.
- Any database DAOS is manages must be an NSF, as it does not support NSFDB2 databases.
Does DAOS have any special configuration options?
Fortunately, DAOS is not something that you turn on and then have no control over. DAOS lets you control how big an attachment must be before it removes it from a document and moves it to an NLO file. It also lets control other things such as how long an NLO file stays around after all tickets have been removed.
There are also new server console commands related to the DAOSManager process (called DAOSMGR), and new features of other server commands. For example, compact has new arguments related to enabling DAOS, namely "load compact mail\mailfile.nsf –c DAOS on."
Caveats to be aware of before implementing DAOS
There are also some things that must be aware of before implementing DAOS:
Your backup process must change. When attachments are initially stored in the OS, the directory of NLO files needs to be backed up, in addition to the databases on the Domino server that you were backing up before. When performing the backup, it's a good idea to back up your databases first, then the NLO files.
If you back up the NLO files first, but a new message comes in with an attachment later, it is possible that the email would be backed up, but the related NLO would not.
- If copying/replicating a DAOS-managed database from one server to another (or to a client) where DAOS is not enabled, the attachments are re-added to the NSF, so it will be much larger. Make sure that the new destination has the necessary disk space to handle the database with all of the attachments added in.
- NLO files should not be copied (at the OS level) from one server to another. The files are encrypted by the Domino server ID. If they are moved to another server where a different server ID file is used, the NLO files are useless.
What do you do if you need to move a DAOS-enabled database from one server to another server to make it DAOS ready? You don't need to do anything, just use the Admin client to create a copy/replica. DAOS and Domino will do the rest. They add the attachments back onto one server and remove them from the other server.
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|ABOUT THE AUTHOR:|
Michael "Mike" Kinder is a senior application developer and administrator with over 12 years experience in the Lotus Notes/Domino environment, including work with BlackBerry and Barracuda products. He is currently building a Managed Solutions/Call Center company in Northern Maine. He is available for consulting opportunities in both development and administration. He can be reached at firstname.lastname@example.org.
This was first published in February 2009