I have a storage group with a database that is about 100GB in size. I have no storage limitations as this database is sitting on a SAN with plenty of disk. I am wondering though if at this point I should break out a new exchange database in this same storage group and migrate all the users in the 100G over to a new database? I have no problems in back-up or recovery windows but the on-line database maintenance windows are surely getting longer. This database has about 350 users.

really up to you. If your SLA is being met, then there probably is no reason. However, I like smaller databases in 2010 and beyond. ( I know you are on 2007) for a number of reasons. Biggest one is to keep the seed/reseed time down. Now, if the 100GB size makes you nervous, then by all means move those mailboxes to some new stores.

Thank you. So I assume that if I move all these users to a new database the size of the database will be much less than 100GB when all the users have been migrated? Also, would it make sense to make a new storage group or would it be ok to make a new database in the current storage group that has the 100GB database? Of course that 100GB database would eventually be deleted when all the users are moved out.

Hi, I have a rule of thumb. The smaller the DB the better as it will be quick to restore/backup. Usually I would have 1 storage group and have 1 db assign to it but this really depend on your topology and business requirement. It is possible that some of the db size is due to whitespace but when you move all the mailboxes to the new db you might see a size difference.

Thanks Michael. Would you consider 100GB "large" in the scheme of things? Also, I assume it is still in best practice to have two databases in a storage group? What would be the downside to that? alex

I dont consider 100GB "excessively" large, no. Its actually best practice to have one mailbox store per storage group, so create a new storage group for each new mailbox store. The reason for that is recovery and logging. Transaction logs are tied to the storage group.

Thanks Michael. Would you consider 100GB "large" in the scheme of things? Also, I assume it is still in best practice to have two databases in a storage group? What would be the downside to that? alex I agree with A_D. 100GB is not large at all. But having all the mailboxes in one db is high risk as it can get corrupted and everyone will be effected.. By spreading the mailboxes over different SG/DB it lower the risk.

really up to you. If your SLA is being met, then there probably is no reason. However, I like smaller databases in 2010 and beyond. ( I know you are on 2007) for a number of reasons. Biggest one is to keep the seed/reseed time down. Now, if the 100GB size makes you nervous, then by all means move those mailboxes to some new stores.

Thank you both. I have a couple of follow-up questions. 1. One of my storage groups/mailbox database has 350 users in it. Lets say I dont want to create another storage group and my sole purpose is to shrink the size of the database. I assume I dont want to use ESE util to do that? Could I just create a second database in that same storage group, move all 350 users to that new database and then delete the old database? I would then only have two databases in that storage grop temporarily and then eventually end up with only one database. 2. Or would it be better to just make a new storage group/database move 150 or so users to that database and balance things out a bit? 3. somewhat off topic, but if I need to resize a LUN and make it larger and extend a volume the exchange database is on, should I turn off the information service first before that is done. I think disk manager complains about that when extending a volume, or at least warns of a potential issue.

Thank you both. I have a couple of follow-up questions. 1. One of my storage groups/mailbox database has 350 users in it. Lets say I dont want to create another storage group and my sole purpose is to shrink the size of the database. I assume I dont want to use ESE util to do that? Could I just create a second database in that same storage group, move all 350 users to that new database and then delete the old database? I would then only have two databases in that storage grop temporarily and then eventually end up with only one database. 2. Or would it be better to just make a new storage group/database move 150 or so users to that database and balance things out a bit? 3. somewhat off topic, but if I need to resize a LUN and make it larger and extend a volume the exchange database is on, should I turn off the information service first before that is done. I think disk manager complains about that when extending a volume, or at least warns of a potential issue. To answer your questions. 1. Your first suggest is doable and can be done without much problems. 2. The problem you will encounter with question 2 is that, if you move 1/2 to the new SG and say the 150 mailboxes is 50GB. Then your initial SG/db will not shrink and contain all the whitespace. What I would do is to create 2 SGs/DBs call it SG02/DB02 and SG03/DB02 and move 1/2 to SG02 and the other 1/2 to SG03. Then delete the original SG. This way you have the DBs shrink without running any ESEutil command and also a less likely corrupted DB. 3. I would stop all the exchange services before doing it as the O/S itself when have to reallocate the disk space.

Thank you both. I have a couple of follow-up questions. 1. One of my storage groups/mailbox database has 350 users in it. Lets say I dont want to create another storage group and my sole purpose is to shrink the size of the database. I assume I dont want to use ESE util to do that? Could I just create a second database in that same storage group, move all 350 users to that new database and then delete the old database? I would then only have two databases in that storage grop temporarily and then eventually end up with only one database. 2. Or would it be better to just make a new storage group/database move 150 or so users to that database and balance things out a bit? 3. somewhat off topic, but if I need to resize a LUN and make it larger and extend a volume the exchange database is on, should I turn off the information service first before that is done. I think disk manager complains about that when extending a volume, or at least warns of a potential issue. To answer your questions. 1. Your first suggest is doable and can be done without much problems. 2. The problem you will encounter with question 2 is that, if you move 1/2 to the new SG and say the 150 mailboxes is 50GB. Then your initial SG/db will not shrink and contain all the whitespace. What I would do is to create 2 SGs/DBs call it SG02/DB02 and SG03/DB02 and move 1/2 to SG02 and the other 1/2 to SG03. Then delete the original SG. This way you have the DBs shrink without running any ESEutil command and also a less likely corrupted DB. 3. I would stop all the exchange services before doing it as the O/S itself when have to reallocate the disk space.

Thanks again. If you were me, which method would you prefer....#1 or #2. I am thinking #2 would be better and more flexible.

Suggestion #2 is good. you would setup more than one DB, this will let you do the maintenance and reduce the time for online defragmentation. i do follow the same practice at all my clients.

Thanks again. If you were me, which method would you prefer....#1 or #2. I am thinking #2 would be better and more flexible. I always suggest and use #2 as my primary option. As it will save alot of headaches in the long term.

Suggestion #2 is good. you would setup more than one DB, this will let you do the maintenance and reduce the time for online defragmentation. i do follow the same practice at all my clients.

Hi all , I need some one to help me out for the server sizing of 350 users and mailbox size would be 2GB/mailbox.I need to install all the roles. Please suggest me if i can install all the roles (except edge server) on 1 single OS. also specify the sizing for edge transport role. Please tell me the hardware requirements and also let me know if its recommended to install all roles on same OS. Thanks You.