Re: New server: SSD/RAID recommendations?

På torsdag 02. juli 2015 kl. 01:06:57, skrev Craig James <cjames(at)emolecules(dot)com
<mailto:cjames(at)emolecules(dot)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).
 
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