Setting the linux shared memory size
902970Nov 27 2012 — edited Nov 27 2012Hi,
I am a little bit confused about the kernel parameters, can you please share your opinions about this one please.
The shared memory for the tt in the linux kernel is computed as below:
shared mem = perm size + temp size + log size + 7 MB overhead
but when i look at the linux sysctl.conf i saw that there is a big value for the share memory setting(default) like ~68 GB, then i think that i should not override/lower this value. What is your opinion? Setting the value as default (68 GB) makes my DB perform bad ? Or setting it to the computed value as in the equation makes it much faster ?
# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736
kernel.sem = 250 32000 100 100
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
Thanks alot.