There's no way to *not* run SIS on Exchange, is there? There can be multiple "I"s (an Exchange server can have multiple mail databases, with several sharing a single transaction log) but there is always at least one shared store.

Great to hear they've moved back to Domino!

@1, well that makes it look all that more impressive. I've often heard MS fanboys mention the much vaunted space savings because of this.

I also said "slightly better". This was actually a very big understatement on my part. It is somewhere in the region of a 16-19% decrease over MS Exchange.

Single-Instance-Storage is always on with Exchange, as Ed says.

I'm assuming that your data was a live set of mailboxes, or a backup from a live server that was restored to a test network. That'd be a fair comparison.

Like Domino's Shared Mail system, the single-instancing is done at the time of mail delivery. So if the Exchange Information Store was populated by importing mail into mailboxes rather than having accounts send mail to each other, it will have no single-instancing going on at all.

This has often bitten people migrating to Exchange, who seem to think that they'll get the space savings immediately on migration - when in fact they won't get any real savings worth talking about until long after the mailboxes have been migrated, and enough of the staff from the migration period have left and had their mailboxes removed...

And of course the single-instancing can be broken after delivery anyway. If someone edits the email after receipt - the body of the email that is, not just follow-up flags etc - then they get their own copy that's separate from the single-instancing.

Finally, the biggest shortfall of single-instancing was always that it's per Information Store. So if you have ten Information Stores and send an email to everyone across all stores, you'll have ten copies of that email - one per Store.

Also, if you move a user from one store to another, their single-instancing is broken and all messages become individual ones - a major pain when you look at how small the limits for each Store have been until very recently.

All in all, Single Instance Storage made sense in 1997, when 16Gb for an Information Store was a huge amount. But as 16Gb has become peanuts, Single Instancing seems to have become a burden that gets in the way rather than any kind of boon...

Anyway, I was just wanting to confirm that your data was in fact single-instanced before the test. It sounds like it was, but it's always worth checking! ;-)

@3, yes this was a live mail box conversion. I picked a random one for the metrics that was a fair size for a comparison.

While I would agree this would seem like a 1990's technology, as was Shared mail and I guess one could quantify DAOS as that too, many, many customers have expressed interest in DAOS because of the burgeoning size of mail files. Not a solution I know (delete some crap, right?), but it is definately front of mind for managers and higher ups right now.

...then this becomes a very interesting case study. Because then the savings will be 40%+... one line: "Migrate from Exchange 2003 to Domino and save 40% on server disk space on your existing hardware. And get hundreds of other collaboration benefits for free."

Wow, wouldn't that be powerful, and that would be in the context of mail alone.

@5 - Ed, I agree wholeheartedly a very, very powerful message. Once I double check that 40% figure of course ;)

Was this a true all-indexes-included count? Had Domino built all of the sortable permutations you might use? Did you include the FT Index size as well?

If no, I'd guess that the resulting impact with Domino would still be smaller by including them, but I figured you want a true apples-to-apples comparison.

I'm not sure that's apples to apples, Erik -- how does Exchange handle search? I thought it was really all in the Outlook client. As an example, Outlook Web Access only displays <100 results for any search. Some Notes users run off of server-based indexes but not all users do (I don't, for example).

I agree that view indicies would have an impact but there are all sorts of other impacts. For example, did Darren use single copy template in the Domino environment?

The first blush results seem pretty good to me.

@7, FT Indexes are not stored in the nsf file, so no they are not included. I did open the inbox and all docs view before looking at the file size. I've just check the mail file in question and it has been fully used and email delivered to it in the last two days (inbox, sent, folders, etc). It is just over 2.2GB which is still smaller and my guess is that is mostly new content (these guys send a lot of attachments) and view indices.

@7 & 8, I don't know how Exchange handles the search which is why it wasn't included. All design elements ARE contained in the mail file.

was i size shown in Exchange or ost/pst file size?

In a comment on my Blog Wild Bill reported interesting figures from a move from Domino to Exchange:

{ http://www.wissel.net/blog/d6plinks/SHWL-7LFCVJ#comment-00A160DEBCB64677C125750300489387 }

A net increase of 480%. I wonder who's head did roll after that.

Sorry i will try again with the correct words in place.

How was the size calculated on the exchange side was it from exchange admin or pst/ost file.

I'm curious about this mail file size.. we run 500 MB quotas and force users to archive or delete. We have applications that run over 1 GB...

I have found that the larger they get, the harder they are to manage. Not only is it time consuming to manipulate bigger files, but everything done on them takes longer (compact,fixup, etc) .... then when you start looking at the views built in the database - views necessary to give users an acceptable level of perfomance and you notice that these larger files with thousands of documents are eating up a lot of space with just view indexes... well, you can see where I'm headed, the bigger the DB, the bigger the mess...

Is Exchange any different when it comes to these things? SIS aside, given the limited gains, can MS manage to give good performance and minimize wasted space?

@10, checking now....will post back once I know.

@11, ahem. Wow.

@13, I didn't say a 2GB Domino mail file was a good idea. The next stage on this client is to implement archiving. ;)

@8/Ed - I'm not an expert on Exchange searching/indexing... I'm just playing Devil's Advocate here since something with this much "sizzle" could easily end up as an IBM press release headline. If it does, ideally it's as solid and as defended a claim as possible.

For example: with DAOS in 8.5, if I have a mail database with 5 GB of attachments and 20 MB of data would I claim that "Domino 8.5 reduces mail file size by 95%+" just because the .NSF shrank?

The "apples-to-apples" comparison as I see it would need all appropriate view indices built, all user-initiated sort-orders for those views built, etc.

Just open Outlook, perform one of each general user action (view/open/search/etc.) Do the same in Notes. Compare *disk space* consumed.

I hope it's as good as it sounds.

Wow - spam filter ate my comment. I'll try again:

@8/Ed - I'll post my response on your blog.

and restored.

For work with mails advise use-Recovery Toolbox for Outlook,as far as i know tool is free and has many features,it "allows to recover *.ost files, when Microsoft Exchange Server gets out of order and your data may be lost,open damaged files, you can open your corrupted *.ost file and estimate data losses,can convert *.ost files to *.pst files, that can be easily opened by any email client, compatible with Microsoft Outlook,convert your *.ost to *.pst, but to extract a list of files in such formats, as: *.eml. *.vcf and *.txt,allows to view a ost file and avoid extracting, for example, 50 Mb of your content, you can extract all files from .ost viewer mail, than just to copy and paste emails and contacts, that you need,view ost file runs under all versions of Windows operating system, such as: Windows 98, Windows Me, Windows NT, Windows 2000, Windows 2003, Windows XP and Windows Vista.

"