I don't think this is possible in current architecture. I think easiest for this is to dynamic part of PGA in SGA :) On Thu, Feb 18, 2010 at 12:00 PM, Thomas Roach <troach@xxxxxxxxx> wrote: > Tanel, > > Is it possible for Oracle to eventually have AMM and hugepages support? > > I think I recall some blog posts by Kevin Closson on this topic and I don't > recall if it was a limitation with the memory being able to dynamically > resize and hugepages not supporting that? > > Thanks, > > Tom > > > On Thu, Feb 18, 2010 at 11:02 AM, Tanel Poder <tanel@xxxxxxxxxx> wrote: > >> Hi Sherrie, >> >> The memory which is reserved for PGA_AGGREGATE_TARGET will not show up in >> /dev/shm as it's not shared (PGAs are still allocated using process-private >> memory). >> >> You can query V$MEMORY_DYNAMIC_COMPONENTS to see how Oracle is currently >> using the memory: >> >> SQL> select component, current_size from v$memory_dynamic_components where >> component like '%Target%'; >> >> COMPONENT CURRENT_SIZE >> ------------------------------ ------------ >> SGA Target 545259520 >> PGA Target 293601280 >> >> >> Note that hugepages are not used with AMM on Linux so you may be not >> getting all the performance out of your hardware... >> >> -- >> Tanel Poder >> http://tech.e2sn.com >> http://blog.tanelpoder.com >> >> >> On Thu, Feb 18, 2010 at 9:51 PM, Sherrie Kubis < >> Sherrie.Kubis@xxxxxxxxxxxxxxxxxx> wrote: >> >>> We have a 3-node (each 32 gb ram) Linux RAC cluster running Oracle >>> 11.1.0.7, housing 4 instances with a total memory_target of 8.75 gb. OEM >>> shows 29% ram is used. We are using AMM. >>> >>> >>> >>> The free -mt command shows: >>> >>> >>> >>> total used free shared buffers cached >>> >>> Mem: 32189 31519 669 0 1250 25168 >>> >>> -/+ buffers/cache: 5101 27088 >>> >>> Swap: 32767 39 32728 >>> >>> Total: 64957 31559 33397 >>> >>> >>> >>> It looks like tmpfs is 16gb: >>> >>> df -k /dev/shm >>> >>> Filesystem 1K-blocks Used Available Use% Mounted on >>> >>> tmpfs 16481056 5604532 10876524 35% /dev/shm >>> >>> >>> >>> We are seeing 5.6gb of memory used, so I'm confused about why the SGAs >>> are defined to consume 8.75gb, but we only see 5.6gb used. I read that the >>> SGA, by default, takes 60% of memory_target and pga gets the rest. Because >>> there are not yet many connections, is this why we see a lower value? >>> >>> >>> >>> Does the tmpfs at 16gb mean we can only use 16gb of ram for our >>> databases? >>> >>> >>> >>> Any insights would be appreciated. We are just starting out with Linux >>> and Posix-Style shared memory management, quite different than shared >>> semaphore memory segments that we were used to. >>> >>> >>> >>> *Sherrie Kubis * >>> >>> Southwest Florida Water Management District >>> >>> >>> >>> >>> >>> >>> >>> IMPORTANT NOTICE: All E-mail sent to or from this address are public >>> record and archived. The Southwest Florida Water Management District does >>> not allow use of District equipment and E-mail facilities for non-District >>> business purposes. >>> >>> >>> >> > > > -- > Thomas Roach > 813-404-6066 > troach@xxxxxxxxx > -- Christo Kutrovsky Senior Consultant Pythian.com I blog at http://www.pythian.com/blogs/