I'm trying to understand Exchange 2003. So from what I can understand by googling is that when a large mailbox is deleted, lets say 10GB, it does not free up space on the hard drive. Instead it adds 10GB of white space in the database. Also if I understand correctly an offline defrag must be done to reclaim this empty space, which it does by creating a new database and copying over the old. Will it not free up the space automatically? Is there any risk to doing this? As far as backup goes, does Exhange handle backup itself or does it need to be done by a 3rd party program? thanks.
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Exchange 2003 database size
- Thread starter lathode
- Start date
There is always risk in taking a database down and performing maintenance on it. I can tell you that over the years I have never had an issue. I will also tell you that the safest way to hand;e this would be to create a new dB and move everyone over to it. You will have a fresh dB and will have none of the white space. This requires disk space but you will need 110% of the dB size to do the offline defrag so you may as well just create the dB. Then users are only effected for short periods of time while the mailbox is moved. I've gone this route many times and it is the best way to do it.
swatbat
[H]F Junkie
- Joined
- Apr 25, 2001
- Messages
- 13,052
Exchange has retention policies in it that also keep data after you delete it.
For backing up you want a 3rd party program that can flush the exchange logs once it knows it has a good copy.
For backing up you want a 3rd party program that can flush the exchange logs once it knows it has a good copy.
Backing the dB or logs is not going to clear our white space and recover hard drive space. Mention of the logs reminded me about circular logging. When moving a huge number of mailboxes from one dB to the other you may want to turn on circular logging depending on how much room you have for logs. If you don't the logs blow up quickly.
hutchingsp
Limp Gawd
- Joined
- Dec 24, 2006
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- 150
Unless you're really running it tight on disk space I wouldn't go spending any time trying to reclaim 10gb of white space - the minute the defrag finishes you're going to be eating into it.
You can check how much white space there is in the database(s) by looking in the application logs for 1221 events during the online maintenance window.
Backups are way more important than white space. You want to be sure you're getting backup done and that they are Exchange aware online backups as otherwise your transaction logs won't be purged.
Windows inbuilt ntbackup works great at backing up Exchange 2003, or depending what you use to backup your other stuff you may have an Exchange agent for that product.
You can check how much white space there is in the database(s) by looking in the application logs for 1221 events during the online maintenance window.
Backups are way more important than white space. You want to be sure you're getting backup done and that they are Exchange aware online backups as otherwise your transaction logs won't be purged.
Windows inbuilt ntbackup works great at backing up Exchange 2003, or depending what you use to backup your other stuff you may have an Exchange agent for that product.
If you want to get an accuate number for how much whitespace you have use the following command
ESEUTIL.EXE /MS [database.edb]
You will need to have the database unmounted to do this. Also, pay attention to both dumps it outputs.
If you stand to gain a crap ton of space, backup the DB and do an offline defrag (allow aaprox 4 hours for 16GB of data)
As long as you make a backup, you will be OK. I have not had an offline defrag screw up a DB yet
ESEUTIL.EXE /MS [database.edb]
You will need to have the database unmounted to do this. Also, pay attention to both dumps it outputs.
If you stand to gain a crap ton of space, backup the DB and do an offline defrag (allow aaprox 4 hours for 16GB of data)
As long as you make a backup, you will be OK. I have not had an offline defrag screw up a DB yet