[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[LDM #GBJ-864447]: Couldn't lock database for writing errors

Hi Rosie and Steve,

re: McIDAS deleting LDM shared memory segments?

> Yes McIDAS is installed.  A few cronjobs use it but a McIDAS session is
> not kept up on it.

I think Steve was substituting 'McIDAS' when he really meant 'GEMPAK'.
The reason for the comment is that some sites that run GEMPAK implemented
draconian procedures for cleaning up shared memory segments and semafores.
Since McIDAS itself cleans up the share memory segments that it creates,
McIDAS-related shared memory expunging would have to have been done by
someone implementing a procedure to clear out shared memory segments.

> We have never seen this happen before..

I have seen this in the CentOS VM in which we are running our UNIWISC
and FNEXRAD image creation processing in AWS.  My "solution" for that
installation was to drop back to LDM-6.8.1 since it was a good, stable
release in the pre-shared memory segment days.  That being said, however,
newer attempts of running a current LDM in CentOS 6.6/7.1 VMs in AWS
have been entire successful.  I have not figured out what is different
on or original AWS VM.

> and why would it start after an ldm restart?

It shouldn't as the shared memory segment will be created at LDM

> Suggestions for how to  prevent this?

The problem would need to be completely understood before proposing
a procedure for preventing it.


Unidata User Support                                    UCAR Unidata Program
(303) 497-8642                                                 P.O. Box 3000
address@hidden                                   Boulder, CO 80307
Unidata HomePage                       http://www.unidata.ucar.edu

Ticket Details
Ticket ID: GBJ-864447
Department: Support LDM
Priority: Normal
Status: Open

NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.