mailscanner (Solaris 2.6) Could not open file
Chang Kai Cheong
kcchang at HKUSUA.HKU.HK
Tue Feb 10 01:23:29 GMT 2004
On Mon, 9 Feb 2004, Spicer, Kevin wrote:
> Its probably been tipped over the edge by the MyDoom virus. IIRC these limits
> apply to processes and their children, so...
> 5 mailscanner processes * 100 message batches * 2 queue files per message = 1000 files
> Then we've got the output header files (another 500 files), then any attachments/ bodies
> being scanned (say 2 parts per message maybe another 1000). And thats before Spamassassin,
> file command etc.etc. Okay I admit that maybe all of these aren't open at the same time -
> but you can see how quickly they can be used up when the server is busy.
> The very fact that taking the messages out of the queue clears the problem suggests it is a
> symptom of the number of files involved.
Actually, I suspected it was file descriptor problem and hence I lowered
the number of child from 10 to 5, max. message per scan from 100 to 80 and
increase the file descriptors as my first step.
However, I was confused by why MailScanner cannot restart successfully.
The first (and subsequent) child process would get the "Cannot create +
lock headers file" at retart of MailScanner. I don't think the file
descriptors would be used up immediately upon the restart of MailScanner
(no message files should have been opened yet).
I will try further up the number of file descriptor to observe whether the
problem was still observed.
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