Archiving Questions: Do Tiered Storage and Stubbing make sense?

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Tom — Wed, 23 Feb 2011 19:59:45 GMT

For some of us, cost is not the issue. Our end users expectations are such that archiving wityout stubbing is a non-started, particularly when indexing has not occurred. MS appears to be trying to eat their gold partners by introducing Archiving 1.0 in exchange 2010, but those "in the know" realize that true to MS form, it won't be ready for production until Service Pack 3.

That said, for a green field implementation, it is probably OK to start here. For those that have stubbing solutions already deployed, it is a non-issue.

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

ArchivingGuru — Tue, 05 Oct 2010 18:47:38 GMT

Not all 3rd party Archiving solutions require software to be installed for the stubbing functionality to work. Also, most 3rd party Archiving solutions offer stubbing as an option, it is not mandatory.

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Ask Perry — Fri, 10 Sep 2010 23:06:18 GMT

@Jason, I don't think you are getting the core point about tiering and how it increases the cost.

I did cover the case of SSD's in my first video - blogs.technet.com/.../getting-the-conversation-started.aspx. But going through this might work better on paper.

SSD's are faster from a random IO perspective (and in particular on reads). However, they are very expensive on a per byte basis. For drives that you can install on a server they are on the order of 50 times the cost per byte of a near-line SATA drive. Worse than this, the projection on cost per byte is not converging over time.

Ok, so lets take your idea and put all the indexes and headers in our database on a set of SSD's and all the other data on the big slow drives. A conservative estimate is that indexes and headers account for over 10% of the total space used in our databases.

So lets take a specific case of 500 users with 2GB of space actually used for each user. Total logical space is 1TB. You could buy a single 2TB drive for each set of 500 users and another drive for each logical copy that you think you need to protect against hardware, network, datacenter and human error. Each of those near-line SATA drives is going to cost you a couple hundred dollars.

Your alternative is to replace the SATA drive with a drive that is 10% smaller (lets say we can get away with a 1.5TB drive instead of 2TB with a very generously estimated savings of 50$) and ADD another SSD drive for the index that is at least 100GB in size. Where do you think you can buy server-ready SSD's for less than 50$ for 100GB? You can't even buy MLC flash for that kind of price. Net you have increased your costs with tiering not reduced it.

This scales up of course. But the estimates for the case of 10,000 users each with 5GB of storage would elliminate a lot of rounding up that helped make the costs seem closer than they are.

Perry

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Markus K — Tue, 31 Aug 2010 10:48:21 GMT

What I do miss is Tiering beyond the current common SAN and DAS technology, no mention of SSD(see comment Jason). Plus getting really small mailboxes for your live data makes it possible to have less powerful mailbox servers. What I miss is any numbers on how the usage pattern of a dedicated set of archive servers and dedicated live mailbox servers can effect the numbers of mailboxes (for live data as they get smaller) or archives (as the performance hit is lower) per database. Then tiering does make sense, because you might be able to sell different RTO's (Koolhand comment) and buy hardware more specific to the requirements.

And there's nothing wrong with aggressive mandatory archiving rules, if it beats having costly quota's and .pst sprawl on fileservers (and backup) or data-loss.

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Frank T — Wed, 25 Aug 2010 15:44:15 GMT

If you don't have access to another site or data centre to replicate too, then you are still stuck with shipping tapes offsite periodically. I think it's those folks who need to worry about recovery time in the event of a disaster. (Of course they are probably also the ones who could be considering moving it all to the cloud...) They'd want to be able to restore tier 1 data before the old archive stuff. But that doesn't mean that the data needs to be on different types of disks. The other thing to remember is that Exchange 2010 doesn't need very fast disks to begin with... slap some big RAM in your servers and chances are that the disks you were considering for your "tier 2 cheapo" storage is probably good enough for the whole thing. You can play with the storage calculator to see different combos.

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Jason — Tue, 24 Aug 2010 19:36:02 GMT

If stubbing were part of Exchange's built-in archiving, then client add-ons would be uncessary as either the CAS or the Mailbox roles could still present the entire message to the client; it'd be transparent to the user.

The index and the "data" are already separate... only in on monolithic container (the jet database). Since most of the IO is due to the indexes and headers, if you were able to put them on separate storage, since they’re so small, you could put them on SSD (500GB of SSD in a SAN isn’t that expensive) and put the message bodies on FATA/SATA and you’d have great performance and really cheap storage.

Sure other vendors have implemented stubbing poorl (*cough* *cough* Symantec *cough*), but that hardly means that it cannot be done right (especially if it can be integrated into Exchange).

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Ask Perry — Mon, 23 Aug 2010 21:18:57 GMT

@Paul Yes backup strategies are expensive. Don't do it. That is my whole point. Microsoft has not run backups on any of our internal email for years now because we have bet on our replication strategy and found that is provides more protection for a lot less money. The overall implementation covers the cases of: data protection in the face of multiple server and infrastructure failures; of users and administrators accidentally deleting data; of records retention for legal requirements (I doubt it comes as much of a surprise that our legal department has its fair share of discovery and legal hold activities) and of physical and logical corruption. I think my previous blog posts covers most of those cases in more detail “Exchange Data Protection” and “More Exchange Data Protection – Beyond Replication” .

Perry

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Ask Perry — Mon, 23 Aug 2010 21:18:02 GMT

@koolhand The key point to recognize in replacing a backup strategy with a replication strategy is that recovery time stops being proportional to size of storage and becomes constant. It takes the same 30 seconds or so to activate your replica whether there is 2GB of data or 2TB of data in the database. Partitioning your data simply does not recover your data faster. Check out my blog post on Exchange Data Protection - the video covers this point specifically starting at 2:50.

Perry

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Robert G — Mon, 23 Aug 2010 17:56:24 GMT

I totally agree with Perry's comments about stubbing.. We started going down that route with a 3rd party product and quickly realized what a mess it creates so we are going to deploy Exchange 2010 and use tiered archive storage once SP1 comes out.

I do disagree with his premise that the expensive tier 1 storage would we wasted. Although in larger environments SAN based raid groups might be dedicated to particular applications we often have different apps sharing raid groups as long as it does not create a performance issue. We have very little waste across our SAN.

I also agree with others comments about the SLAs for recovery. Although we will use DAGs groups with one passive copy recovery time is still a big issue not only for disaster recovery where we want the Tier 1 data back fast but also for things like restores to RSGs. If we have a true disaster which takes out our one and only data center when we will be recovering only the T1 data first and then going after the archive stores once all other critical systems are restored.

re: Archiving Questions: Do Tiered Storage and Stubbing make sense?

Brian — Sun, 22 Aug 2010 01:40:55 GMT

The other thing missed by MS in this case is that I may want more copies (greater redundancy/HA) of my primary storage and less for my archive. Their cost saving argument assumes I have the same number of copies of my archive databases/mailboxes.