The Notes/Domino 8.5 public beta has been out for a couple weeks now, so I wanted to take a moment to highlight one of the new features that will help reduce those wonderful storage costs and large mail file sizes!  Storage costs consistently rate as one of the highest components of Domino TCO and my customers are always asking how they can better manage mail file storage.  To help with that (and the ever increasing size of your mail files out there), enter DAOS.

With DAOS you can consolidate the storage of attachments for all users of a Domino server.  Common content is stored only once (outside the Notes database) and DAOS manages reference counts on the shared content.  For example, in the "old way", when a user sends an attachment to a group of people, each person receives a copy of that attachment in his/her mail file.  

In the "new way", with DAOS, when an email is sent to multiple recipients with an attachment, one reference of the attachment is stored in DAOS, and the recipients of the message get a"small ticket" or pointer to the DAOS store.  In addition, DAOS keeps a count of how many "links" are provided.  

So, less copies of an attachment in a mail file translates to less I/O on the server, faster database operations such as compact, less network bandwidth used and a significant reduction in the amount of storage used.

How does it work?

DAOS is local to the Domino server and is not cross-server.  Each mail.box on the Domino mail server is DAOS-enabled.  Then, when a message is deposited in the mail.box, any attachments are removed and stored in DAOS.  Only a reference to the attachment is routed for each target database on that mail server.  I've already gotten a couple of questions from customers on how it works, so I thought I'd share some of the more "pressing" things I've been asked:
 
  • If an attachment is edited and re-attached, it is detected as a new file attachment and stored separately
  • If the message is replied to or forwarded, DAOS still only uses the pointer or "small ticket" for the new messages
  • For non-DAOS enabled databases, the entire attachment is copied (so for local replicas, the full attachment will be in the local mail file)
  • The current plan is to allow the administrative client to see DAOS reference counts, attachment sizes, etc. and administer the DAOS store

How do I use it?

DAOS is optional and is a service specific to each Domino server partition.  Also, it requires transaction logging be enabled on the server and the ND8 ODS.  Participation is a per-database property setting that can be enabled via a compact command.  In addition, DAOS objects count against the quota of the mail file and are reported as part of the file size.

And since I'm sure you'll ask -----

DAOS is completely different from and shares No code with Single Copy Object Store (SCOS)!

So - it's pretty cool and something I'm sure you will want to take a look at - either in the beta or once 8.5 goes production later this year.  I'll post more information about it and how it works as we come closer to the release date.