URL:
Reporter RHNID:
Section: -
Language: en-US (English)|
Workaround:

Description: Student Guide states that 0.5 seconds is 500 centisecs when it is actually 50 centisecs .
----------------------------------------------------------------------------------------------
When using a database server workload, an administrator may make the following type of adjustment: vm.dirty_background_ratio=3, vm.dirty_ratio=80, vm.dirty_expire_centisecs=500, and vm.dirty_writeback_centisecs=100. With this configuration, the machine will start writing out dirty pages from cache if they are over 3% of system memory, but will not force writes until dirty pages are over 80% of system memory. Every one-tenth of a second (100 centiseconds), the system will check to see if pages have expired and need to be flushed to the I/O subsystem. Lastly, pages expire from cache after .5 seconds (500 centiseconds). Using this configuration, pages expire from cache more quickly, but the kernel will continue to do background writes of the dirty pages unless they are consuming a ridiculous amount of system memory.
----------------------------------------------------------------------------------------------