Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is there a limit on the number of "stores" you can have on an Exchange server? It seems that it takes a very long time to repair one large store and we are thinking it might be better to divide the stores up into smaller chunks so we can bring accounts back up faster if it happens again. Some people were thinking there was a maximum number you could have. This seems a bit arbitrary to me....

share|improve this question
up vote 2 down vote accepted

With an Exchange 2003 Standard server it is 1 Mailstore and 1 Recovery Mail store. With the Enterprise version it is 4 + 1 Recovery Mail Store.

Of course the better question is "Why do I have to recover my mail store enough that this is a concern?" You really should not need to repair your mail store unless something goes horribly wrong - like power dropped and your battery on your RAID controller was dead so you lost changes.

Additionally, smaller mail stores won't help you that much. The repair programs need to go through every data structure in the JET database, inspect, verify, attempt repair, re-inspect, re-verify it is a process that is just going to take a long time. However, you really should not have to repair an Exchange data store all that often - if ever.

share|improve this answer
I'd disagree re: "smaller mail stores won't help you that much". Nobody should be using Exchange 2003 today, if they can help it, but having said that using multiple storage groups with multiple mailbox databases can allow you to take a failure of a spindle hosting a storage group while maintaining availability for the other storage groups. Certainly, your storage shouldn't fail in this manner, but you can gain some addt'l risk tolerance by spreading out the storage. Exchange 2003 is an I/O monster, too (what w/ the 3GB virtual address space limitation), so multiple storage groups ... – Evan Anderson May 31 '11 at 16:55
... can allow you to spread out the I/O over multiple spindles to increase the mailbox capacity of a given server. 64-bit Exchange makes this less of an issue, but if you're trapped in a 32-bit Exchange world the multiple storage group / database functionality does have some usefulness. – Evan Anderson May 31 '11 at 16:56
@Evan oh yes i agree multiple stores are useful, i was talking specifically about the "very long time to repair" a mailbox store. – Zypher May 31 '11 at 17:02

From KB 821748 - HOW TO: Add New Mailbox Stores in Exchange Server 2003

Exchange 2003 uses mailbox stores and public folder stores, and these are referred to as databases. In Exchange 2003, you can configure up to five stores (either mailbox stores or public folder stores) in up to four storage groups, and you can have a maximum of twenty databases for each Exchange 2003 computer.

This applies to the Enterprise edition of Exchange 2003. The Standard edition limits you to a single mailbox store of 16GB, or 75GB if you have SP2 and make a small registry change.

share|improve this answer
+1 - That's the most technically correct answer. You can have up to 20 databases hosted in 4 storage groups (5 databases per storage group) with Exchange 2003 Enterprise Edition. You can also have one Recovery Storage Group, too, on both Standard and Enterprise Edition. – Evan Anderson May 31 '11 at 16:52

Graeme Donaldson and Zypher are correct. That is actually a good reason to go to Exchange 2007/2010. In the standard edition, you can have 5 databases in either 2007 or 2010, and in the enterprise edition, you can have 50 in 2007, and 100 with Exchange 2010.

Even with the standard editions, you can take your heaviest users and break them up over three databases, and put the rest on one. I usually leave one open for future use. This can really be noticeable help, for example, if you are doing a granular restore in Backup Exec since it has to stage the entire database, and if it is broken up, it takes much less time.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.