Whats the guest OS? I have been able to get Oracle to perform just as well on Virtuals as it does on Physicals. I suspect the settings are pretty similar.
On Mon, Nov 27, 2017 at 3:06 PM, Fernando Hevia <fhe...@gmail.com> wrote: > > > El 27 nov. 2017 15:24, "Don Seiler" <d...@seiler.us> escribió: > > Good afternoon. > > We run Postgres (currently 9.2, upgrading to 9.6 shortly) in VMWare ESX > machines. We currently have effective_io_concurrency set to the default of > 1. I'm told that the data volume is a RAID 6 with 14 data drives and 2 > parity drives. I know that RAID10 is recommended, just working with what > I've inherited for now (storage is high-end HP 3Par and HP recommended RAID > 6 for best performance). > > Anyway, I'm wondering if, in a virtualized environment with a VM > datastore, it makes sense to set effective_io_concurrency closer to the > number of data drives? > > I'd also be interested in hearing how others have configured their > PostgreSQL instances for VMs (if there's anything special to think about). > > > > If the storage was exclusively for the Postgres box I'd try > effective_io_concurrency somewhere between 8 and 12. Since it is probably > not, it will depend on the load the other VMs exert on the storage. > Assuming the storage isnt already stressed and you need the extra IOPS, you > could test values between 4 and 8. You can of course be a lousy team player > and have PG paralelize as much as it can, but this eventually will piss > off the storage or vmware manager, which is never good as they can limit > your IO throughput at the virtualization or storage layers. > > Cheers. > > > > -- Andrew W. Kerber 'If at first you dont succeed, dont take up skydiving.'