Yes Anand, I had posted this question in a forum a long time ago and did not get a satisfactory reply. Thank you for your update. I would like to use this thread to further expand on the GRD functionality. 1) Besides the DBA, Role, Mode and SCN, what other information does GRD contains? 2) Is there a way (event, etc) to dump the contents of GRD? Thanks -----Original Message----- From: racdba-bounce@xxxxxxxxxxxxx [mailto:racdba-bounce@xxxxxxxxxxxxx] On Behalf Of Anand Rao Sent: Tuesday, July 26, 2005 12:40 AM To: racdba@xxxxxxxxxxxxx Subject: Re: GRD maintenance in RAC Hey! i think i have read this question on Metalink a long time ago !!! ...not sure of this is the same Ahmed :-) not a problem, Both LMD (GES) and LMS (GCS) maintain the DLM database which is otherwise called as the GRD in Oracle 9i and 10g. LMD performs a very crucial function called Deadlock Detection as well lock database canning and lock conversion. So, locking operations are made possible because LMD handles the lock database or shall we say maintains the GRD. There are many resource structures inside the GRD and these structures are what comprises the GRD and maintained by GCS and GES. In Oracle 9i, LMON did the DLM reconfiguration (on instance crash or instance join/leaving). In Oracle 10g it is the LMS which does the remastering. The housekeeping task of cleaning the DLM database (cache) is also done by LMON and i think LMS takes this job from Oracle 10g. Other than this i believe PMON has a lot of DLM calls stacked away in its code in RAC enabled databases. But, PMON does not do any GRD maintenance. In 9i, LMS maintains structures related to lock messaging which is also stored inside the GRD. corrections are welcome. regards, anand On 26/07/05, Hameed, Amir <Amir.Hameed@xxxxxxxxx> wrote: > > > Hi folks, > Per the "Oracle 9i2 RAC Concepts" manual, page 3-6, "The GCS and GES > maintain a Global Resource Directory to record information about > > resources". Does anyone know what parts of GRD are specifically maintained > by GCS and GES respectively. Also, are these the only components that > maintain GRD or are there other processes that also participate in the > maintenance? > > Any feedback will be appreciated. > > Thank you > Amir