After much cogitation I eventually went RAID-less. Why? The only option for hardware RAID was SAS SSDs and given that they are not built on electro-mechanical spinning-rust technology it seemed like the RAID card was just another point of solid-state failure. I combined that with the fact that the RAID card limited me to the relatively slow SAS data-transfer rates that are blown away by what you get with something like an Intel NVME SSD plugged into the PCI bus. Raiding those could be done in software plus $$$ for the NVME SSDs but I already have data-redundancy through a combination of regular backups and streaming replication to identically equipped machines which rarely lag the master by more than a second.
Cheers, Steve On Wed, Nov 2, 2016 at 1:20 PM, Scott Marlowe <scott.marl...@gmail.com> wrote: > On Wed, Nov 2, 2016 at 11:40 AM, Joshua D. Drake <j...@commandprompt.com> > wrote: > > On 11/02/2016 10:03 AM, Steve Atkins wrote: > >> > >> I'm looking for generic advice on hardware to use for "mid-sized" > >> postgresql servers, $5k or a bit more. > >> > >> There are several good documents from the 9.0 era, but hardware has > moved > >> on since then, particularly with changes in SSD pricing. > >> > >> Has anyone seen a more recent discussion of what someone might want for > >> PostreSQL in 2017? > > > > > > The rules haven't changed much, more cores (even if a bit slower) is > better > > than less, as much ram as the budget will allow and: > > > > SSD > > > > But make sure you get datacenter/enterprise SSDs. Consider that even a > slow > > datacenter/enterprise SSD can do 500MB/s random write and read just as > fast > > if not faster. That means for most installations, a RAID1 is more than > > enough. > > Just to add that many setups utilizing SSDs are as fast or faster > using kernel level RAID as they are with a hardware RAID controller, > esp if the RAID controller has caching enabled. We went from 3k to 5k > tps to 15 to 18k tps by turnong off caching on modern LSI MegaRAID > controllers running RAID5. > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
