MTA DAT Files

[labrooks]

We are running Exchange 5.5 and are backing up with Veritas Backup Exec. I noticed today that there are quite a few "File "DB000xx.DAT" in use - Backed up files listed (7 pages of them). These are on the Bridgehead server. Could someone tell me what these files are and if they need to be cleaned out? Thanks.

Lois Brooks

 

[Wibble]

is the backup working successfully....i'd check the logs.....it may not be clearing the archive bit. You'll get a handful which will make up the enviroment dat files and they will be quite old....leave these alone!!!

run eseutil /Mk edb.chk

this will tell you when the last good backup was made.

 

[labrooks]

According to the Backup Exec log file the backups are successful. So maybe I should leave well enough alone!

 

[rws]

These files are in the mtadata directory. They have nothing to do with your databases. When the mta processes messages, it creates .dat files as it needs them, but it does not delete them when done. It saves them in case it needs them again. The designers of the mta thought this would be more efficient than creating new ones every time. To reduce the number of files, from exchsrvr\bin, run mtacheck /rd /rp /v /f c:\mta.txt. The first 2 switches will clear out any old directory and public folder replication messages, the v is for verbose, the f will log to a text file (which you can put anywhwere and call anything).
I've seen this reduce the mta on a busy server from 10,000 dat files to 2000.
MTA must be stopped to run it, and there can't be any .dat files in the mtacheck.out folder.

 

[Wibble]

there is no point in running mtacheck with /rd /rp....all you are doing is temporarily removing directory and public messages. They will be resubmitted....and only serves to buy you breathing space if you have horrendous queues.

Ignore what the backup exec logs are saying.....check the amount of disk it claims it is backing up against the physical stores...it can be very misleading....More importantly dump the checkpoint file to see when it last got backed up. Without a clean backup you will NOT purge the dat files.