Hi all, would anyone be able to offer any advice on the estimated time to completion for a full offline defrag of a mailbox database (Exchange 2007) that is approximately 116gb in size. We have recently split up our original database (that is 116gb) into x3 databases (mailbox database 1, 2 and 3). I've moved all mailboxes so they are split evenly across all three databases, so in theory they should be approximately 40gb each in size. Now this work is complete, we need to reclaim the disk space the original database has taken up (it will have a lot of white space in the edb file), but I've no idea how long it takes roughly to run in order to plan downtime for the mailbox being dismounted. Any rough estimate would be appreciated if possible (I realise it is hard to do considering you need to take size / white space / hardware specs etc into consideration). Many thanks,

I would suggest you to dismount the DB, rename the EDB file and mount the DB back. This will ensure that a fresh DB is getting created. I have did this with exchange 2003 and worked well.-Cheers Shaba

Thank you Shaba, and absolutely, that is all part of my plan, however not my question though! :-) I'm trying to find out how long it is going to take (roughly) for a defrag of a mailbox database that is approximately 100gb in size. If I plan to do this work overnight, will it run into the next business day? As mentioned, I realise this is a difficult question to answer, but anyone with experience of running this might be able to give me a rough answer of "yes, our 80gb database took X hours". Thanks again.

I think this is a very difficult question to answer as it is based on your hardware. I would question your reason for doing this - offline defrags a not needed in 2007 but, you may have a valid reason.

reason is, we have added x2 new mailbox databases to split our mailbox load across 3 databases. The original database (which is 116gb) has a lot of white space in it, so to shrink the size back to somethig near where it should be I need to defrag it offline.

Depends on many factors, have seen 4 - 12 GB per hour so I would go with 4GB to make my estimate with and hope for better. I assume you have 110% of free disk space for that largest database i.e. 116GB * 110%? If not you will need to have that to do the defrag and my estimate assumes the temp space is on a local drive and not a share to an alternate location which would alter the time it takes greatly. That said why not Optionally Create a fourth Database Move all the remaining users from the original DB into the 4th DB OR deposit them temporarily into the 2nd or 3rd DB Take the original offline Rename that Original EDB for safe keeping Mount that original store up and Exchange will say hey the DB files are gone and if you continue we will create new DB files, yeah OK create the new files New Blank DB is created Moving users back into new DB that is empty and now all DBs are balanced Copy the Original Database off to portable media and kill off the Original DB from the server now you have 116GB freed up and all users balanced in fresh databases with no long term down-time Troy Werelius www.Lucid8.com Search, Recover, & Extract Mailboxes, Folders, & Email Items from Offline EDB's and Live Exchange Servers with Lucid8's DigiScope

I did offline fragmentation only once and it took 2 days to get completed - 150GB db. If you have an alternate option like I and Troy mentioned, Go for that.-Cheers Shaba

Depends on many factors, have seen 4 - 12 GB per hour so I would go with 4GB to make my estimate with and hope for better. I assume you have 110% of free disk space for that largest database i.e. 116GB * 110%? If not you will need to have that to do the defrag and my estimate assumes the temp space is on a local drive and not a share to an alternate location which would alter the time it takes greatly. That said why not Optionally Create a fourth Database Move all the remaining users from the original DB into the 4th DB OR deposit them temporarily into the 2nd or 3rd DB Take the original offline Rename that Original EDB for safe keeping Mount that original store up and Exchange will say hey the DB files are gone and if you continue we will create new DB files, yeah OK create the new files New Blank DB is created Moving users back into new DB that is empty and now all DBs are balanced Copy the Original Database off to portable media and kill off the Original DB from the server now you have 116GB freed up and all users balanced in fresh databases with no long term down-time Troy Werelius www.Lucid8.com Search, Recover, & Extract Mailboxes, Folders, & Email Items from Offline EDB's and Live Exchange Servers with Lucid8's DigiScope