Excessive physical memory used on our Oracle 11.2.0.4 database servers running on RedHat 6 -

this first post on stackoverflow please gentle. on our live database servers seeing excessive physical memory being used. after upgrading memory

we had memory shortage issue on our live database server effected operation of database, live server had 8gb of physical memory. 8gb in hindsight low upgrade 16gb straight away 16gb reported being used on top , free -m. upgrade memory again, again memory used reported in top , free -m

the current output on top, free -m , dstat -m show :

tasks: 608 total, 2 running, 602 sleeping, 0 stopped, 4 zombie cpu(s): 18.1%us, 1.5%sy, 0.0%ni, 78.9%id, 1.4%wa, 0.0%hi, 0.1%si, 0.0%st mem: 32872264k total, 32449036k used, 423228k free, 172064k buffers swap: 6291444k total, 1284776k used, 5006668k free, 25308944k cached

pid user pr ni virt res shr s %cpu %mem time+ command 42754 mislve 20 0 12.8g 542m 535m r 93.8 1.7 4:37.94 oracle 43278 mislve 20 0 12.8g 1.3g 1.3g s 7.8 4.0 0:28.44 oracle 23227 mislve 20 0 12.8g 159m 155m s 3.9 0.5 0:06.54 oracle 5120 mislve -2 0 12.8g 14m 14m s 2.0 0.0 46:55.13 oracle 5130 mislve 20 0 12.9g 96m 84m s 2.0 0.3 27:25.16 oracle 5136 mislve 20 0 12.9g 239m 238m s 2.0 0.7 6:32.02 oracle 10428 mislve 20 0 12.8g 1.4g 1.4g s 2.0 4.6 0:36.53 oracle

lln1p-band01:mislve$ free -m total used free shared buffers cached mem: 32101 31860 241 10222 167 24874 -/+ buffers/cache: 6819 25282 swap: 6143 1254 4889

lln1p-band01:mislve$ dstat -m ------memory-usage----- used buff cach free 6825m 167m 24.3g 233m 6825m 167m 24.3g 232m 6825m 167m 24.3g 232m 6825m 167m 24.3g 232m 6826m 167m 24.3g 231m^c

the size of database sga 13.463gb

sql> show sga

total system global area 1.3463e+10 bytes fixed size 2281432 bytes variable size 6912213032 bytes database buffers 6308233216 bytes redo buffers 240676864 bytes

rightly or wrongly configured database use automatic memory management (amm) temporary measure wanted see if tried ring fence memory used oracle database stop excessive use of ram. set memory_max_target 16gb , memory_max_target 14gb. know these values excessive , should not used amm on live oltp system disabling , rizing sga , pga accordingly.

sql> show parameter target

name type value

---

archive_lag_target integer 0 db_flashback_retention_target integer 1440 fast_start_io_target integer 0 fast_start_mttr_target integer 300 memory_max_target big integer 16g memory_target big integer 14g parallel_servers_target integer 64 pga_aggregate_target big integer 1500000000 sga_target big integer 0

but ring fence of 14gb seeing ramn being used. suspect memory being used in operating system file cache. theory oracle session memory not being released operating system due database server leak.

i did run: sync; echo 3 > /proc/sys/vm/drop_caches try , clear page cache had made impact on memory usage

here detail memory server :

lln1p-band01:mislve$ cat /proc/meminfo memtotal: 32872264 kb memfree: 423780 kb buffers: 185776 kb cached: 25300460 kb swapcached: 48340 kb active: 18999184 kb inactive: 9041360 kb active(anon): 11505660 kb inactive(anon): 1514952 kb active(file): 7493524 kb inactive(file): 7526408 kb unevictable: 0 kb mlocked: 0 kb swaptotal: 6291444 kb swapfree: 5002792 kb dirty: 72 kb writeback: 0 kb anonpages: 2509516 kb mapped: 9673360 kb shmem: 10466304 kb slab: 605716 kb sreclaimable: 394984 kb sunreclaim: 210732 kb kernelstack: 12736 kb pagetables: 3517352 kb nfs_unstable: 0 kb bounce: 0 kb writebacktmp: 0 kb commitlimit: 22727576 kb committed_as: 17502452 kb vmalloctotal: 34359738367 kb vmallocused: 218536 kb vmallocchunk: 34359505336 kb hardwarecorrupted: 0 kb anonhugepages: 1079296 kb hugepages_total: 0 hugepages_free: 0 hugepages_rsvd: 0 hugepages_surp: 0 hugepagesize: 2048 kb directmap4k: 8192 kb directmap2m: 2088960 kb directmap1g: 31457280 kb

the version on our redhat operating system : 2.6.32-696.3.2.el6.x86_64 version of our oracle database : oracle database 11g enterprise edition release 11.2.0.4.0 - 64bit production

has experienced similar or know causing high memory usage , how remedy issue.

any or advice appreciated.