We have always been informed by one of the UK Vars that we should
configure ipcstr connections and not ipcshm when running on AIX. Does
anybody have any idea why and what would be the ramifications of uisng
ipcshm instead?

I have a weird problem which has only surfaced since we did a massive
migration of firmware, OS, IDS, and application software and during
this change somebody changed which connection would be used to the
server for 4GL programs running on the same system from onsoctcp to
onipcshm.

Everything is working OK apart from a very intermittent problem with
onbar/ISM where devices become unmounted for no apparent reason. I
don't see why this change would be related to the problem but as a
wiser man than me once said
"If you're looking for a needle in a haystack you can't help clutching
at straws"

regards

Malcolm

mweallans@panacea.co.uk wrote:
> We have always been informed by one of the UK Vars that we should
> configure ipcstr connections and not ipcshm when running on AIX. Does
> anybody have any idea why and what would be the ramifications of uisng
> ipcshm instead?
>
> I have a weird problem which has only surfaced since we did a massive
> migration of firmware, OS, IDS, and application software and during
> this change somebody changed which connection would be used to the
> server for 4GL programs running on the same system from onsoctcp to
> onipcshm.
>
> Everything is working OK apart from a very intermittent problem with
> onbar/ISM where devices become unmounted for no apparent reason. I
> don't see why this change would be related to the problem but as a
> wiser man than me once said
> "If you're looking for a needle in a haystack you can't help clutching
> at straws"
>
> regards
>
> Malcolm
>

If I remember correctly, when IBM released the powerPC version 4 CPU
some changes were made to the semaphore handling. These changes made
sometimes an ipcshm connection unexpectedly hang. A workaround to this
problem was to change ipcshm to ipcstr.

Still if I remember correctly, the problem was solved in IDS 7.31.UD2
I don't think there has been problems using ipcshm on AIX since then.

Claus