On 03/06/2018 01:16 PM, Laurenz Albe wrote: > pinker wrote: >> I've got cutomer with really huge RAM, now it's: >> total used free shared buffers cached >> Mem: 3102111 3052596 49515 208801 992 2961185 >> -/+ buffers/cache: 90418 3011693 >> Swap: 8191 1 8190 >> >> (free -m) >> >> and before it was twice more (6TB). >> >> and trying to figure out how to set dirty_ratio & dirty_background_ratio >> parameters. Even for normal sized server those default sizes are to high, >> but now would be ridiculously huge, respectively 1,24TB and 300GB. >> I'm thinking about 1 percent for dirty_ratio and not using >> dirty_background_ratio because it's not possible to set it below 1% but to >> set dirty_background_bytes instead to about 1-2GB. >> Maybe someone has got other experience with RAM of this size and those >> settings? > > Yes, you should set vm.dirty_background_bytes and vm.dirty_bytes > and not use the *_ratio settings. > > 2 GB for vm.dirty_background_bytes and 1 GB for vm.dirty_bytes sounds fine. > It should be the other way around: dirty_background_bytes < dirty_bytes regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
