open: Resource temporarily unavailable

[Rita Li]

The first few lines of my daily backup script reads as:-

MSG="Please logout from system BDCIMFG1 now.\n\nScheduled system backup will be run in 1 minute !!!"
echo "\nLogin disabled ..." > /etc/nologin
echo "$MSG"|/usr/sbin/wall
sleep 60
#---------------------------------------------------------------------
echo "Backup the following directories and their sub-directories:"
echo
echo " /mfgpro2/apps ..."
echo " /mfgpro2/asn_uso_bak ..."
echo " /mfgpro2/ndm ..."
echo " /mfgpro2/scripts ..."
echo " /mfgpro ..."
echo " /mfgdata2/common ..."
echo " /develop3 ..."
echo " /develop ..."
echo " /home ..."
echo " /scripts ..."
echo
#
#----------------------------------------------------------------------#
who -u

For the last few days, the log file captured is with output like:-

open: Resource temporarily unavailable
Cannot send to sydai
Backup the following directories and their sub-directories:

/mfgpro2/apps ...
/mfgpro2/asn_uso_bak ...
/mfgpro2/ndm ...
/mfgpro2/scripts ...
/mfgpro ...
/mfgdata2/common ...
/develop3 ...
/develop ...
/home ...
/scripts ...

byeung pts/tb Jun 21 23:59 1:11 2535 10.0.83.108
zsheng pts/tc Jun 22 03:20 . 4501 10.0.84.20
hxhuang pts/ta Jun 22 02:21 1:38 4321 10.0.84.255
sprod7 pts/td Jun 22 00:52 0:05 3058 10.0.84.249
byeung pts/te Jun 22 01:48 2:12 3558 10.0.83.38
rpluo pts/tf Jun 22 03:32 0:06 4589 10.0.85.124
xildu pts/tbb Jun 21 14:05 11:04 25575 10.0.83.214
lhchan pts/ttd Jun 21 13:25 10:53 9439 10.0.83.63
sydai pts/t1d Jun 21 13:39 13:10 3847 10.0.86.226

However the syslog.log does not have any warning/error messages

I am not sure what goes wrong & this script has been working well for 10+ years already & first time to notice such message

Thanks for any help that can be provided

Regards,
Rita

[Steven Schweda]

I know nothing, but according to "man wall":

[...]
DIAGNOSTICS
Cannot send to ...
The open on a user's tty file failed.
[...]

So, I'd assume that you have a user named
"sydai", whose terminal is busy, or in some
other way unavailable.

> [...] this script has been working well for
> 10+ years already [...]

I'd say that it still is working, but "wall"
is trying to warn someone who isn't listening
(for one reason or another). If you can
figure out who "sydai" is, you might be able
to walk over and tell him that you're about
to take the backups.

As "man wall" suggests, see also "man mesg".
No doubt there are other things which would
block a broadcast message to a user's
terminal. For example, if I were doing a
Kermit file transfer over a serial line, I
certainly wouldn't want your "Please logout"
message to appear in the middle of my data
stream. I don't kow what "sydai" is doing,
but apparently he/she/it doesn't want it
interrupted this way.

[Rita Li]

Need a system reboot to fix up the problem

[Anshumali]

It may not be appropriate to restart the system. Either the session is not getting ended or it may be what we know as ghost session/ improperly closed/hung session.anyways.......