Re: New server: SSD/RAID recommendations? - Mailing list pgsql-performance

From Andreas Joseph Krogh
Subject Re: New server: SSD/RAID recommendations?
Date
Msg-id VisenaEmail.44.70ed435cef1739b1.14e4c07dd3d@tc7-visena
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In response to New server: SSD/RAID recommendations?  (Craig James <cjames@emolecules.com>)
Responses Re: New server: SSD/RAID recommendations?
Re: New server: SSD/RAID recommendations?
List pgsql-performance
På torsdag 02. juli 2015 kl. 01:06:57, skrev Craig James <cjames@emolecules.com>:
We're buying a new server in the near future to replace an aging system. I'd appreciate advice on the best SSD devices and RAID controller cards available today.
 
The database is about 750 GB. This is a "warehouse" server. We load supplier catalogs throughout a typical work week, then on the weekend (after Q/A), integrate the new supplier catalogs into our customer-visible "store", which is then copied to a production server where customers see it. So the load is mostly data loading, and essentially no OLTP. Typically there are fewer than a dozen connections to Postgres.
 
Linux 2.6.32
Postgres 9.3
Hardware:
  2 x INTEL WESTMERE 4C XEON 2.40GHZ
  12GB DDR3 ECC 1333MHz
  3WARE 9650SE-12ML with BBU
  12 x 1TB Hitachi 7200RPM SATA disks
RAID 1 (2 disks)
   Linux partition
   Swap partition
   pg_xlog partition
RAID 10 (8 disks)
   Postgres database partition
 
We get 5000-7000 TPS from pgbench on this system.
 
The new system will have at least as many CPUs, and probably a lot more memory (196 GB). The database hasn't reached 1TB yet, but we'd like room to grow, so we'd like a 2TB file system for Postgres. We'll start with the latest versions of Linux and Postgres.
 
Intel's products have always received good reports in this forum. Is that still the best recommendation? Or are there good alternatives that are price competitive?
 
What about a RAID controller? Are RAID controllers even available for PCI-Express SSD drives, or do we have to stick with SATA if we need a battery-backed RAID controller? Or is software RAID sufficient for SSD drives?
 
Are spinning disks still a good choice for the pg_xlog partition and OS? Is there any reason to get spinning disks at all, or is it better/simpler to just put everything on SSD drives?
 
Thanks in advance for your advice!
 
 
Depends on you SSD-drives, but today's enterprise-grade SSD disks can handle pg_xlog just fine. So I'd go full SSD, unless you have many BLOBs in pg_largeobject, then move that to a separate tablespace with "archive-grade"-disks (spinning disks).
 
--
Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
 
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