пятница, 30 октября 2009 г.
понедельник, 28 июля 2008 г.
kernel.shmall & kernel.shmmax
kernel.shmall is a total amount of shared memory pages (not bytes) available for allocation systemwide.
Size of the page is determined by `getconf PAGE_SIZE`.
kernel.shmmax is the maximum size of shared memory chunk in bytes (not pages) available for one application.
What does it mean in real wildlife? Well, let's suppose we have here a server with 2 Gb of physical memory and trying to run postgresql server on it. We decide to give a half of whole system memory to PG. So, we type in our command prompt with bash/zsh something like
...and voila! we just did the dummiest thing ever, cause postgresql will have to manage all this gigabyte at it own. We just need to inform him about our intention:
& change shared_buffers to 1 gigbyte =)
Size of the page is determined by `getconf PAGE_SIZE`.
kernel.shmmax is the maximum size of shared memory chunk in bytes (not pages) available for one application.
What does it mean in real wildlife? Well, let's suppose we have here a server with 2 Gb of physical memory and trying to run postgresql server on it. We decide to give a half of whole system memory to PG. So, we type in our command prompt with bash/zsh something like
sysctl kernel.shmall=$((1024*1024*1024/`getconf PAGE_SIZE`))
sysctl kernel.shmmax=$((1024*1024*1024))
...and voila! we just did the dummiest thing ever, cause postgresql will have to manage all this gigabyte at it own. We just need to inform him about our intention:
vim postgresql.conf
/shared_buffers
& change shared_buffers to 1 gigbyte =)
суббота, 26 июля 2008 г.
Подписаться на:
Сообщения (Atom)