On Mon, 11 Dec 2006, Nik Conwell wrote:
I'm using the UW mailutil to transfer mailboxes from UW to Cyrus (2.3.7). It
uses APPEND, specifically multiappend (single APPEND with multiple messages
being appended). Cyrus-imapd handles this multiappend by creating stage
files for each appended message and leaving the file descriptor open. The
problem is that after 240 messages, we run out of file descriptors and so an
open() of the next stage file fails with EMFILE. I updated /etc/cyrus.conf
to make the max fds be 1024 (AFAICT kernel MAX) which helped somewhat but not
for larger mailboxes with > 1008 messages.
Shouldn't the multiappend/append be closing the FD for each stage file and
then reopening it later as it needs it?
Do people just tweak their kernels to have some insane number of FDs
available in order to compensate for this?
Or, do people not use mailutil and instead use something that issues multiple
append commands rather than a single append with multiple e-mails?
We run with a much, much larger number of file descriptors here. I've
increased the system limit to around 200k (/proc/sys/fs/file-max on
linux). This is for the day-to-day running of Cyrus, so I don't know if
you would need a higher limit for running mailutil (but I doubt it).
In practice, each of my backends has only used a maximum of around 12k
file descriptors, but I'd hate to run out! :)
Andy
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