Re: shared memory after server kill

Sean Davis wrote:
 > I am using macosx, pg 7.4.3.  I had a server running and working.  I
 > tried to bring the server down with 'pg_ctl stop', which failed (server
 > running on localhost).  I then (timidly) killed the postmaster process.
 >
 > When I tried to bring the server back up, I got an error similar to:
 >
 >   FATAL:  could not create shared memory segment: Cannot allocate memory
 > DETAIL:  Failed system call was shmget(key=1, size=1081344, 03600).
 > [...]
 > I have 4 Gb of memory, with approximately 2.6 Gb available (via top)
 > and a vast swap.  What is going on?

When you kill the postmaster process forcibly, it doesn't
release the shared memory segments that it had allocated.

Use the "ipcs" command to list all currently allocated
shared memory segments, and use "ipcrm" to remove them.
I've once written a small shell script which basically
does it (I've only tested it on FreeBSD, but Mac OS X
should be similar enough):

#!/bin/sh -
ipcs | awk '($1=="m"){print $2}' | xargs -n 1 -t ipcrm -m

Of course, you can also solve the problem the Windows way
(i.e. reboot).  ;-)

Best regards
   Oliver

--
Oliver Fromme, secnetix GmbH & Co KG, Oettingenstr. 2, 80538 München
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