Linux SGA/cache memory question
KenFMar 10 2011 — edited Jun 23 2011I’m puzzled trying to figure out how much memory is available
Red Hat Enterprise Linux AS release 4 (Nahant Update 8) 64bit
Oracle Enterprise DB 10.2.0.3
32 Gig physical Ram
I have 4 databases with SGAs ranging from 2 to 12 gig
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0xde5381a8 32769 oracle 640 1612709888 22
0xf299ecb0 65538 oracle 640 3156213760 21
0x7401f5b0 98307 oracle 640 12886999040 81
0x16e079cc 163844 oracle 660 2686451712 160
Yet free –m
total used free shared buffers cached
Mem: 32187 31945 242 0 338 27142
-/+ buffers/cache: 4464 27723
Swap: 6142 384 5757
And gnome-system-monitor suggest I’m only really using approx.. 4.5 gig of memory with 27 gig in cached.
Vmstat indicates no paging on the system.
My limited understanding of cached was that linux used this or I/O buffering. But now I’m beginning to think this also includes my SGA.
Can someone help me better understand where the shared memory is accounted for, or point me toward something that will ?
Thanks
Ken F.