[Mailman-Users] 'Read-only file system' when processing posts

[Jesse B. Crawford]

Hello,
I'm having a rather frustrating problem that I haven't been able to find
anyone else running into and I'm a bit stumped. I have mailman installed
from source on a Fedora 27 machine, and I'm using it along with Postfix
in a configuration using an aliases file and virtual domain map managed
by Mailman, as described in the manual.

When I try to email to a list, the following error is produced:

Feb 28 20:30:45 alpha postfix/local[4278]: 87DFA4018657D:
to=<listname at lists.domain.tld>, relay=local, delay=0.23,
delays=0.05/0.01/0/0.17, dsn=5.3.0, status=bounced (Command died with
status 1: "/usr/local/mailman/mail/mailman post listname". Command output:
Traceback (most recent call last):
   File "/usr/local/mailman/scripts/post", line 69, in <module>     main()
   File "/usr/local/mailman/scripts/post", line 64, in main
tolist=1, _plaintext=1)
   File "/usr/local/mailman/Mailman/Queue/Switchboard.py", line 136, in
enqueue     fp = open(tmpfile, 'w')
 IOError: [Errno 30] Read-only file system:
'/usr/local/mailman/qfiles/in/1519878645.717417+32700e28bfadb80bc2aa1db465be6ad2122f6a69.pck.tmp'
)

I have added newlines to make the stacktrace a bit more readable. Of
course you can see that the error is "Read-only file system" but I can
assure you that the file system is not read-only. I have run the
check_perms command (no problems found) and also checked manually that
the 'mailman' user should have write permissions in that location. I
have 'su'd to the mailman user and written in that directory to be
certain. I have also checked that the permissions on
/usr/local/mailman/data/aliases and
/usr/local/mailman/data/virtual-mailman and their corresponding .db
files are correct.

Of course all of this is assuming it's a permissions problem, which
ought to produce a different exception from Python. Any ideas about what
the "Read-only file system" exception could possibly be about?

As far as other potential causes, selinux is disabled on this machine
and the file system looks fine as far as space and inodes available.
Plenty of other things are writing in var without trouble.

Thanks in advance for any ideas on this issue.

-- 
Jesse B. Crawford
jesse at jbcrawford.us
https://jbcrawford.us
GPG 0x4085BDC1