Transport service failure and accumulating TRN*.LOG files, filling disk

kellybarlow used Ask the Experts™
Windows SBS Server 2008

Exchange 2007

Suddenly my long-running Exchange box has started crashing the Transport service. The sequence goes something like this:

Start the Transport service (either manually, or through reboot) with clean Queue folder.
Mail flows fine, but as it does, the mail.que file begins to grow, and TRN*.LOG files accumulate.
Eventually the disk fills up, the Transport service can't write to disk any more, and it craps out.
If I clean space from the disk, then try to restart, The Transport service begins the sequence of replaying the TRN*.LOG files, but it never finishes and eventually the service stops (again).
If I rename the Queue folder to Queue.old and create a new, empty Queue folder, Transport service starts, but we go through the exact same sequence again.

I've investigated this post and performed as many of these functions as seem relevant on an Exchange 2007 installation -
I turned ON circular logging (it was off on all my mailbox databases)
I've disabled Transport Agents
I've disabled antivirus (Defender)
I don't know what to do next. Ideas?
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Saif ShaikhServer engineer

Do not purge any log files now if you want to investigate log files growth.

I would suggest to to follow articles-

and see why the log files are growing rapidly. There could be many reasons for log files growth. See for all database what is the log files growth rate I mean in 1 min how many log files generate i.e. more then 50 then there is a problem.
Saif ShaikhServer engineer

Log file growth is happening from users MAPI or IPhone.  Try to find the root cause. You can use the logparser tool from internet to parse all collected logs. This will tell you which users are responsible for log file growth.
transport logs have nothing to do with database logs

how big does the mail.que get ?
how many log files do you get ?
how much free space is on the volume, and what size is the volume ?
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Saif ShaikhServer engineer

I thinks I did not read the question correctly and was under impression that the issue is with exchange transaction log file growth.

My Bad...........

What is the exchange version and service pack ???
@Saif Shaikh you appear to have also missed that it is Exchange 2007 on SBS 2008, would you like to borrow some reading glasses ?
Saif ShaikhServer engineer

Thank you..)


Gentlemen, apologies, but  a reply I THOUGHT I posted 2 days ago didn't post.

ArneLovius, the volume has around 18 GB available. The mail.que database has gotten as large as 5-6 GB with over 1,000 log files before finally filling the disk and crashing.

I would think that the TRN*.log files would get purged at a time during posting to the mail.que database (especially if this is a circular log). Do you know what the trigger is for these logs being deleted?


Thanks, DrDave242. I stumbled on this, but couldn't find anyone with a big dumb attachment in their outbox. The symptoms sound EXACTLY what I'm experiencing.
is there another volume you can move the transport queue to ?


ArneLovius, I moved it before posting. I wish that were the trick, but thanks.
if you can;t see anythign in teh queue manager after clearing and restarting the transpoprt service, I woudl suggest moving transport to a drive with considerably more than 18 GB free space, although I would in now way usually suggest trying this in a production environment, a USB connected disk might be useful in this situation...
Still without a resolution, Monday evening I signed on to each email account using Outlook to check - once again - if there was a large email attachment stuck in someone's mailbox.

I didn't find one,  but as I signed on to each one, I also compacted each mailbox and rebooted each computer.

Once completed, the server experienced no further issues. I've been running for two full days without any of the previous symptoms. I can't say that this definitively fixed the issue, but it is - indeed - fixed.

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